Manipulated by my stepson

So, last weekend while my husband was out of town I went out with a guy from work. We were at a small restaurant in a dark corner. We were kissing and making out. Before you judge me, my husband is gone and a woman has needs too. Anyways, my stepson came to the same restaurant at the same time we were there. And of course, he saw us. Later that evening at home he confronted me. He threatened to tell his stepfather unless....you guessed it....unless I had sex with him!!! Sex with my stepson!?!?! I begged him not to tell his stepfather about my one little indiscretion. He just smiled and walked away. Then this morning as I lay resting I feel a hand on my leg. Startled I look up. It's my stepson. He is here to collect on the debt. I try to talk him out of this. I tell him how wrong it is. But he ignores me. He continues to touch my body. He slides my panties aside and begins fingering my pussy. I protest but my body betrays me. He and I both can hear the sloppy wetness.