ok so long story short i have been seeing a girl i dated 4 years ago that currently has a boyfriend. i hadn't talked to her in 4 years and we ran into each other ( small town ) things have been happening the last 3 months spending time and a physical relationship, but she has yet to end things with him. i have made my intentions clear that i want to be with her and that i don't want to be the other man. I KNOW THIS IS ALL WRONG.. but i became emotionally involved and its hard for me. she spent the last few nights with me and today went to a family party with him. which i knew about. she called me later on when she got home and we had a good convo, about a lot of stuff and she brought up how he wanted her to stay with him tonight and that she said no. she asked to see me tomorrow and that was goodnight. i recieved an encouraging text a few minutes later so i decided to be spontaneous and suprise her.. well she wasn't home.. she was at his house, this was roughly 11:30, i don't drive by peoples houses for fun but when she wasn't home i had to know. I KNOW all of this is wrong, i just need some help understanding why myself and others seem to go through this..

some people are so lucky in love, i know this isn't the ideal situation but ive been single a while and felt like the way she explained things it was over with her bf. she has been very affectionate and re assuring. so i fell for her again. and now im heartbroken, again. maybe she just didn't want to tell me she was going to save me from worrying? or to appease him?.. in my heart i know if it was real she would have left him immediately if things were right.. im just venting and have nobody to talk to.. i always seem to get myself in these situations. it doesn't hurt any less after a few times... .. i have to tell her now that i can't see her anymore. i don't want to call her out on anything, but i need to end it. anyone else have any insight or encouragement, i could really use it right about now. im feeling pretty down..