Im going to try to put this situation as brief as possible i really need help with this. I'm a divorced single parent with an 11 year old son. I don't live with my current partner but have been with her for 11 years now (i got divorced from my wife when i met her). She's got her own house and me too, we don't live together but have been in a relationship for 11 years now. I only come and stay at her house during the weekends (because of work and many other parenting stuff.)The thing is this, she never applies any type of rules to her daughter (18) and her son (16) the problem is that basically her son is a school drop out and has just been playing video games for the last 3 years, he has no responsibilities at home and does nothing to help. Her daughter now 18 is currently working, (talk about her in a moment). The kid does nothing beside playing on the computer all day long. One day he even hit me on the face because a told her mother not to clean his mess for him. That was the first call for me. When he turn 16 her mother allowed his girlfriend to stay at home at nights. He has been sexually active since he was 15, i wasn't ok with that and many other things as well but is not my house i told myself. Her daughter on the other hand also had his boyfriend to come and basically live at home as well, that's when things finally took a turn, both of them had their boyfriend and girlfriend at home that finally made my partner go nuts. She told both of them, her daughter's boyfriend and her son's girlfriend to go or for them to look for a place to live with each of them respectively. Well at least that made his girlfriend and her boyfriend never to come back. The girl finally left the boy only to find another one in a couple of months. The boy started going to the house at night and then he left. then he started to stay late till the morning but at the end he left. The drop that spilled the cup happened last weekend when i was at her house, the girl sleeps at the room right next to ours. basically I was watching a movie when I started to hear all moans and groans from her, it was horrifying, ok is not my biological daughter but I felt inside a cage i didn't know what to do, I felt trapped a wanted to run out of there. her mother was still asleep so at the begging she couldn't hear any of this. I decided to step out of the house to give them time to finish. To my surprise after 30 minutes I went inside the house and into my the partner's room just to find out the moans and groans have turned to screams and "Shit" "Fuck" I was horrified that's when my partner finally woke up, I thought it was the end of the world. To my surprise she just said that they were making too much noise and went to sleep again. The next day when he daughter came out from her room she just said good morning as if nothing had happened and the same for her mother. I was amazed, I couldn't believe it. I can't even think about sex anymore without hearing her moans and screams. Sorry that was kind of long. I'm a really strict person but she isn't, I'm even afraid of going to her house again I don't want to be put through that again in my life. The million dollar question is should i throw the towel? I have been struggling with this type of things for YEARS now and she does nothing to change it and I'm really getting tired of this.