Mother's best friend

I ended up talking to Maria, my mother's best friend. Maria pestered her and she ended up telling her about her love life... When I was stared at the beautiful Maria-san intently, I was so nervous that I couldn't help but fantasize about it. In my fantasy, Maria-san gently leads me, and I'm ecstatic and instantly erection! However, I never imagined that Maria would be watching my crotch, which had been erect in real life...