I got my brother's mother-in-law pregnant

I'm the youngest of three, and the oldest, my only brother, married at 21. His mother-in-law was widowed at 34. Her daughter was born when she was 19, and the daughter married my brother when she was 19. Fast forward three years; I was home on leave and attended a party at my brother's home. Drinks flowed freely; I don't drink alcohol myself, so I stayed sober. My brother's mother-in-law was drunk and became very flirtatious; I went along with the flow. I bedded her and really enjoyed myself, staying the whole night with her. Fucking her again before leaving in the morning; now, six months later, she is pregnant. She knows I'm the father; she wasn't unaware of who was fucking her at the time. But as for the rest of the families, they believe it was a one-night stand. Every time I visit home, we get together for some fun, as she calls it. I'm quite happy to play along. She is financially well off, as is my family.