Since my step-father dies 3 years ago, my mother and I stopped having sex. My step-father knew my mother had a lover, he told her to look for one if she wanted because he wasn't able to have sex because of his disease. What he never knew was that I (her son) was her lover. It lasted for 2 years until he died, after his death my mom stopped having sex with me, and I understood her reasons. A few months ago she came to my place and I knew she wanted to start it again.