This thread seriously made me think how shitty i've had it back then..
First instance: This happened several years ago. I was going away on a trip and I told my bf at that time to not do anything stupid while I was away. While I was in Cali for my trip, my ex's friend messages me (guess he was dumb enough to cheat on me while another person we know was there..)and tells me that my ex was making out with my friend in the theatres. I was in shock and livid. Since I didn't want to have to think or deal with him anymore , I dumped him over skype (sad but true). He told me that he didn't even feel like we were in a relationship anymore and that if I didn't work with my then-friend that he would get back with me. I plainly told him to have fun with her. Also to add salt to the injury, this girl posted on her facebook (tagged me) that she isn't a boyfriend stealer and a slut. She also messaged me that she's so sorry that she had feelings for him with the sad emoji. I told her have fun and good luck with your new relationship. Haven't heard from her or him since.
Second Instance: This was a long distance relationship. .my ex started working in this retail store and met this girl at work. He told me she was cute and would talk/eat lunch with her all the time. One time he drove her home and he told me that she was touching his leg and telling him to forget about me. I told him why would you even be talking to her and hanging out with her while she basically disrespects me? He said it's because she's nice and she's a friend of his. Also my ex did not let me hang out and does not like that I have guy friends (ive known them for years) because he said that all guys are out to get me and they just have one thing in mind. He used that excuse that me having guy friends should amount to him having girl friends. I said please talk dont talk to her outside work and to avoid her. He said hes going to try to avoid her. Few months later, we were having some rough moments in our relationship. During my birthday, he messages me and said :"Happy Birthday, oh by the way drunk. And I fucked ".." (his coworker). I told him okay thats nice and stopped talking to him, blocked him; deleted him from everything.
TL;DR: ex banged his cowoker on my birthday and told me about it.
Today...i am dating a super awesome dude that takes care of me, loves me, and respects me as his other half. I'm glad those days of my life are over and it really does help make you a stronger person.