Awkward things about relationships

When a girl cheats on her boyfriend, sometimes instead of just doing the logical thing and breaking up the guy actually goes on to fight the guy who did things with his girl. The funny thing about this type of scenario is that it is almost always the case that the girl says she is single and cheats or the guy knows the girl has a boyfriend and hooks up anyway. Either way, the girl is cheating and when the boyfriend finds out, he gets mad at her and madder at whoever hooked up with his girlfriend. This is the funny thing about this type of situation which happens a lot, instead of simply blaming her for cheating and ending the relationship, he goes on to express his anger verbally and/ or physically on the male that had affairs with his girlfriend or just simply stays with her although he acknowledges the fact that she cheated on him. However, sometimes the boyfriend may just be with her even after finding out about her affairs because he may just have intentions of staying with her for materialistic and or sexual gains. Although what I just mentioned is also true, sometimes the boyfriend just likes his girlfriend too much for whatever reason and chooses not to break up even though he understands that she cheated and there is a fair chance that she will do it again.
With girls, however, it is different. Some girls would not hesitate to break up once she finds out that her boyfriend is cheating. Even if she decides not to break up, she is not as likely to go after the girl that had affairs her boyfriend unlike the scenario with men being cheated on by their girlfriends. Not breaking up after finding out that she is being cheated has many reasons such as she feels that she probably will not find another guy that has an expensive car, spends lots of money on her, or maybe because she likes him a lot. The thing that is unfortunate and quite common about nowadays is that many girls have abusive relationships in which the boyfriend uses her to just fulfill his needs and mistreats her, cheats on her, and even physically assaults her. What is so ironic about this type of scenario is that, millions of women with such types of relationships for some unexplainable and incomprehensible reason seem to not be able to break up. Even when their friends and others who tell her to simply break up and never contact that man/boy, she tends to stay for a long time and endure the abuse for some reason and then break up or he breaks up with her.