exploring the point of being with "taken" people

writing the title immediately brings about the fact that i have only had one relationship. so exploring my attitude before i got into my one and only relationship shows me that i judged/looked down on relationships. always thought they were a bunch of bullshit. tons of deception. stupid fights over easily solvable issues. tears and making one another "feel bad" for things. i watched many around me growing up in relationships.my mother and father. my mother and her boyfriends after my father. my sisters and their boyfriends. my friends and their boyfriends. one of my best friends growing up had her first sexual experience in an affair with a married man. all the examples i had of relationships, well they fucking sucked. so that helped me to develop this resistance of relationships. i would tell myself i never want to be in a relationship like ive ever seen. i would say that my first boyfriend would be my husband because i would wait that long get into a relationship. i saw that relationships were all about making the other one happy. whatever that meant at the time. which was deception to me. just relating to one another. that was never my idea of a successful partnership. so i resisted relationships. and maybe developed some kinda "fuck u" attitude to relationships in general. which is probably why mine was unsuccessful (aside the many issues within it). wow. ok first time i had sex with someone who had a girlfriend was in college. second guy i ever had sex with. he was a friend of mine. we always had a flirty thing going on. i knew he had a girlfriend. but i saw it as,"hes my friend. us fucking is just two friends fucking. nothing more. nothing less." we fucked, he felt guilty. i did not. we fucked some more. i moved away. he got another girlfriend. we still fucked around. we are still friends to this day. he has a girlfriend now who wants to get married eventually. he feels pressure from her family to do "the right thing". he feels like its something he should do. we have not had sex since hes been with her. but we have had naughty conversations via phone and text. he experiences guilt. so i told him we do not HAVE to be sexual in nature. i enjoy him. sexy time or not lol. so we havent been talking or texting sexually anymore. second time i had sex with someone who had a girlfriend was after recovery from my car accident where i almost died *point to explore/never wrote out this experience*. this one was completely accidental. i was walking home from the library and a guy drove by me and honked his horn. i waved. not seeing who was actually driving the car. i figured they just left on their way until i walked by the parking lot. a blonde haired blue eyed guy was sitting in a car waiting for me. i rarely got hit on by white guys. it was either i made the attempt or we were friends first. i use to think i really intimidated white guys cause i was so straight forward about the fact that i only wanted to fuck with white guys and never been with a blck guy. but this one was straight forward with me. we talked a bit. exchanged numbers and i continued my walk. he called me and came over to the place i was staying. we hung out. talked. one thing i really dug about this guys was he was so intense about us. his heart would speed up and hed place my hand on it and he would get nervous and i thought that was cute. we fucked. he came over and we'd hang out an watch porn and fuck and listen to music and talk. did this until i left to go home. after being home two days he tells me on the phone that not only is he married, but he had a son as well. i was like, wtf? i wasnt so much pissed about it. just surprised that i had no clue. he divorced his wife. he was pretty shitty around that time. i didnt like what he had become with leaving his wife and son came a shit ton of other things. we stopped talking for a while. he came to visit me. it was ok but his head wasnt there. he was in it and somewhere else. when he left i thought to myself "he will never change". we still talk to this day. and hes a completely different person now. so much more self aware and aware of life and honestly cares for people and the world. we do not have a sexual relationship. sex was the basis of us in the past. the both of us are on different shit nowadays. we do have great converstions about life and the things we encounter. third time i had sex with someone who had a girlfriend was a friend i use to live with in the college dorms once i changed schools. my group of friends was me and about 6 guys. we all got long great. hung out all the time. i had a major crush on on of my guy friends. one night i thought me and that guy friend ihad the crush on were going to finally have sex he ended up flaking. so i went and found one of our friends in that group of 6 and i hooked up with him. it was on some drunk reasoning shit. after hooking up, didnt have sex, we were like "ok wtf was that." we knew we were on some drunk shit so we just left it. continued to be friends. year or so went by. he got a girlfriend whom the rest of us didnt really like. mainly because she took some of his time from us. we all went out one night. just me and they guys. we went out. got drunk. we back to my friends house. and he started kissing me. this was surprisingly out of the blue and i did think of his girlfriend for a second. then i thought of "my boy" and she was of no concern any longer. this happened another time with us. he came to get me with a couple friends. we got fucked up and ended up in bed together. i woke up in the morning naked and needing to pee. i put on my cloths cause i thought his friends were still there. went to pee then lay back down. i kept my cloths on though. he was passed out all afternoon and i was just laying in bed with him texting. i hear his door open and he hops up from his dead sleep saying,"thats (girlfriends name)!". i stood up already clothes but my pants zipper undone. shoes in hand, purse in hand, condom wrapper in hand. she walks in, looks at me ( i had a blank expression. i didnt feel guilt about it. didnt hate the girl at all but i didnt know if i was going to have to be physical her because of this.) looks at him (he was completely naked. with the excitement and being half fucked up still he couldnt manage cloths before she came in) starts to cry and runs out the house and down the street. he puts on cloths and goes after her. i left to go home. he texts me later on "its all good. i told her u were coming in to wake me up". wow. she must have really wanted to believe that lie. because it was apparent. they stayed together some months after this before calling it quits. we are still friends to this day. i decided to stop resisting being "taken" and in a relationship so i went out and got in one. i didnt "cheat" when i was in my relationship. i did still talk to my many guy friends and had the opportunity to cheat, but i did not. id appreciate some insight if anyone has any on this. thanks.