I now have my a problem here in that I see my Mother in Law almost daily and I keep thinking there could be something here. She is 15 years older but doesn't look her age at all and she certainly doesn't act the grandmotherly type. Let me provide some background here:
I have been with her daughter for 25 years and we have no kids and have limited to no sex in the last few years due to her medical condition. My wife acts as though she is the grandmother at times and is prudish when it comes to sex and such. My MIL has been divorced from my wife's Father for 27 years after she left him for another man who fed her a story and then he left her 4 years later with nothing. Things got interesting after that...

When I was 28 and she was 43 we were at a family party. Bottom line is I was drinking (knew what I was doing) as was she but she ended up in the same bed as her daughter and I. With my wife sleeping I rolled nude towards my MIL and placed my cock on her ass. She reached down and stroked me as I lifted her t-shirt to suck on her tits. I then pushed her panties aside and began rubbing her clit while fingering her until I made her cum. After she came she guided my cock to her pussy and I slid my cock in gradually. I did 6-10 strokes when she stopped me so I pulled out but then she went to her own bed. The next day she woke me up by placing her hand on my morning wood and kissed me on the lips but have never spoke about it since.

During the time since she had found another boyfriend but he died a few years back. I know she has not had cock in years but I'm trying to get back in there.

Any ideas on how to get back in?