realised mid-act i didnt want to be there and i still finished

this is the one i havent told anyone. cork couple, second meet. we'd had a fine first night a month before. this time we're in their spare room and about ten minutes in something just... clicked off in me. like a light. i wasnt scared i wasnt unsafe nothing bad was happening i just no longer wanted to be there. but i was already there. his face was already there. my husband was already in the other room. so i carried on. i even finished. faked it actually but finished from the outside. drove home thinking what the f is wrong with me. its been a month. i havent told the husband i havent told the couple. i dont know if this is a "real" bad night or if i just had an off day and im being dramatic. 35 hes 39 swinging 3 years