Mother in laws Blackmail Tactics, (edited)

I've been married to my wife for five years. I wouldn't say it's been plain sailing, but we get along most of the time.
We have a very close family, which on my wife’s side can be a blessing but on my side not so much.
The only person I've had a few run-ins with is the mother-in-law. She can be a very feisty woman to deal with, and we've had some right run-ins over the years.
Don't get me wrong, she can be very loving when it comes to her daughter, but with me, it's like a red rag to a bull.
She is in her late sixties. I won't say she kept herself in any good shape, but for her age, she's wearing well, as they say.
Things all changed between us one afternoon on a visit to her house.
I had to drop something off for my wife, which meant I had to visit her mother's domain.
She met me at the door, and after exchanging pleasantries, she let me in to carry the boxes I had to deliver.
“Put them in the kitchen,”. She said.
Placing the boxes on the table, I turned around quickly, and for some reason, she was stood right behind me. How it happened god knows, but she fell forward, and as I reached out to catch her, we both collapsed onto the floor, with her whole body somehow on top of mine.
“Christ, what happened? “ she said.
“ I looked up at her thinking she would kick off at me. We both started to laugh, but then as she lifted herself onto her arms, both her ample breasts fell out of her flimsy gown.
I couldn't help but notice them, she looked down and without batting an eyelid, she said, “Well, at least someone's pleased to see you,” she said.
Not a response I expected from her, knowing how she is with me normally, but as she was on top of me and I had a full unobstructed view of her breasts.
Fully expecting her to initially scream and curse at me for causing this to happen, I was taken aback by her initial reaction.
There didn't seem to be a rush to lift off me as both her legs had opened, and I could feel her warm body on mine. With her legs beeping open, her body was resting on my groin area, and due to the fact she had her tits out, my knob just instantly stiffened.
Feeling this, she looked down at me, saying, “Looks like someone else is also pleased to see me,” she said.
My hard cock now throbbing against her, she could feel its stiffness through her thin gown.
“Well, with flashing those boobs of yours, what do you expect?” I said.
“My daughter must have some right fun with that thing.”
“Sometimes when she's in the mood,” I said.
Then without hesitation, she lowered her breast down onto my face. She also, at the same time, started to move her hips from side to side against my now seriously hard cock.
Again thinking this situation wouldn't last, in an instant, I took full advantage. I had her very hard nipples right there, so I just took each one in turn and gave each one a good suck.
Reaching up with my hands, I cupped each breast as she continued to move her hips against my ever-increasing bulge as both my hands manipulated her soft breasts.
“ god you have warm hands,” she said.
Still with her breasts in my face, I could see the enjoyment she was having as much as I was. I had my mother-in-law’s tits in my hands and her body gripping on my bloody hard shaft.
“ I've not had a cock that close to my pussys in years,” she said.
“Well, you keep moving like that on it. I won't be responsible for my actions,” I said.
With that, she seemed to move faster, rubbing her pussy area on my hard bulge. Her gyrating hips just made things worse. This woman was horny, and to be honest, so was I.
I had my mother-in-law's eager body moving seductively on mine, and I could tell things were getting very hot between us.
This woman, who I had not had any good relationship with over the years, was riding my knob, and I wasn't about to let her stop.
“Christ, Joan, you keep doing that. I'm going to cum in my pants,” I said.
I still had her soft breasts in my hands when she looked down at me. “Well, that would be a waste now, wouldn’t it?” she said.
Rolling off me, she helped me up, her tits still out. She took my hand and led me to her bedroom. Things were about to get interesting.
She closed the door behind us, then as she turned to me, her gown suddenly fell to the floor. Standing in just her panties, she turned to me, saying, “If this is going to get messy, then why waste it?” she said.
Without thinking, in that moment, it just took over us both. I quickly dropped my pants, and as she jumped onto the edge of her bed, lifting her legs, I reached under her to slip off her now very damp red panties.
Again, not thinking about anything else, my hard cock stood ready to fuck my mother-in-law’s mature, hot pussy.
Looking down, I got my first sight of her dark mound with this reddish-pink slit opening up before me, seemingly ready to receive my solid cock.
“Right, let's see what you've got. Get that bloody cock in me and fuck the arse off me,” she again begged.
Holding my cock, I guided it towards her opening, rubbing her slit up and down with my tip. She flipped her head back, letting out a low groan. I could tell she was ready to get up and fucked.
Finding her entrance, I leaned into her. I lowered myself over her body as my cock slid quickly up inside her pulsing wet hole.
That hot sensation alone made what we were doing all the more amazing. My hard cock was being enveloped by her eager, hot mature pussy.
I now had my mother-in-law’s naked body under me. She was begging me to fuck her, so I just went for it. Our two bodies combined into one fast, erotic passion even I didn't expect.
Grunting at me as I pounded the hell out of her pussy, she cried out for me to go harder. She wanted sex, and that's what I wanted to give her.
Both her large breasts bounced in time as my hips just kept thrusting between her open legs. “ Jesus, Brian, you can bloody fuck,” she said.
Grunting at her, my hard, long shaft just pummelled her tight, wet mature pussy.
We both, I could tell, wouldn’t be long until we would cum, to feel that rush of an orgasm. It didn’t take long for her body to react to how I was fucking her pussy, wrapping her legs around my waist, she bucked and twisted her body in time with how hard I was going at her pussy. “ Jesus Christ, you sod, you’re going to make me cum,” listening to her words, I stepped up my incursions, then at that moment of our heated passion, we both just let out a loud scream, arching her back and groaning at me to keep going. I was going like hell when I suddenly thrust in so hard her body moved up higher onto the bed. I was in so deep as my cock just filled her hole with all I could give her. She in turn screamed at me that she was cipumming, and as her orgasm pulsed through her I could feel her pussy walls claiming hard on my still throbbing cock.
Holding myself inside her, to make sure every drop of my cum filled her pussy, I lifted and looked at her. All I could do was say, “ What the fuck just happened? Why the hell did we fuck?” I said.
“ god knows, but my god, you definitely know how to fuck, I've not cum like that in years,” she said.
“What the hell's your daughter going to say?” I said.
“Nothing because she won't find out.”
“ I blame you, those bloody tits of yours,” I said.
Pushing her boobs together, she looked at me, “ What these?”
“Yes, if they hadn't dropped out of your gown, this wouldn't have happened.”
“You grabbed them first.”
“You rubbed yourself on my knob,” I said.
“Well, the look on your face as you fucked me, I guess you needed it as much as I did,”. She said.
“To be honest, it's been a few weeks, so yep, you came in handy for once.”
“Handy, you cheeky sod, that was more than being bloody handy,” she said.
“Yeah, well, at least you got what you were after,” I said.
“I wasn’t after anything, you fucked me remember,” she said.
Lifting off her, my cock just slid out. She also lifted herself up and grabbing a towel, she started to clean herself up.
“So what happens now? We just forget it happened.” I said, pulling on my pants.
“That depends on how you think about fucking your mother-in-law’s pussy.”
“ to be honest, your not to bad, nice pair of tits, that pussy of yours I’m guessing not seen much cock but from what I can tell it’s not bad for its age,” I said.
“ you cheeky sod, I will have you know it get enough cock thank you, I have my friends who make sure of that,” she said.
That’s when it hit me, she does this quite a lot, I guess I’m not the only bloke that she’s he’d recently the way she talking.
Can I ask you a question? Was that you in Oxford the other day, in a café? “In the front window,” she said.
“I don't think so, why?” I asked.
“Well, I pulled up at the traffic lights and looked over to see someone who looked like you kissing a woman. They looked very friendly. The best thing was I managed to get a close-up picture of them,” she said.
In that instant My face dropped.
“How long have you been cheating on my daughter?”
“About a month, I guess. She’s a work colleague,” I said.
“Well, I just wanted to see how easy it was for you to cheat, and having sex with her mother proves you can't keep it in your pants,” she said.
“So if you tell your daughter about me and that other woman, I will tell her about what we just did,” I said.
“ and whose idea you think what we just did was then,” she said.
“ she knows, I enjoy sex, she asked me to see if I could get you to fuck me, to be honest it was easier than I thought,” she said.
“My daughter had her suspicions you were cheating. She asked me if I could confirm it or not. I too thought you were, and what happened? Today proved it when it offered to you on a plate. You men can't help yourselves,”. She said.
“So why let me fuck you if you already had the evidence?”
“ I will tell you why, I needed to prove I was right, and to be honest, it worked. You fucked me, and I must admit it was a good fuck, far better than I expected, even though it was wrong to do so,” she said.
“So this is a shakedown then. So what will it take to delete that picture?” I said.
“Si I’m guessing my marriage is over, or are you going to drag this out and torment me with it?” I said.
“To be truthful, I should tell my daughter everything, confirm to her you are a cheater, but I must admit how you fucked me was better than I thought. So for now I won't say anything to her If you stop seeing that other woman,”.
“ fair enough,” I said.
“ hang on you don’t get off it that easy, I’m keeping this picture, ok, I will tell my daughter that you didn’t try anything but I will say I will keep trying,” she said.
“ I have one stipulation, you make sure from now on you keep my daughter happy, you make sure the sex you have with her is as good as you’ve just had with me,” she said.
“ ok I can do that,” I said.
“ the other thing is at least once a week you pop round her and fuck me as well, until I’m satisfied you not doing anything to hurt my daughter,” she said.
“You kidding? I'm buying your silence with sex, sex with you, her mother,” I said.
“That's the deal or I will tell her everything, and trust me, I can be very persuasive.”
“Well, if that's what I have to do, then sex with you it is.”
I was totally shocked at what she proposed, sex with her to keep quiet, I can handle that.
From then on I fucked her daughter and her mother, what more could any bloke ask for.