No, that is not what I am asking.
Why did you decide to go in a relationship with her? You can love her perfectly well and spend time with her perfectly well without a relationship.
But for most people, being exclusive is a huge part of it. Having the intimacy and the love of your partner for yourself. Besides that, it may also be to make it clear that you expect to be able to rely on them.
I don't think there are a whole lot of reasons to get into a relationship with someone. But in the cases of many, many couples cheating goes directly against the main agreement of a relationship. Essentially rendering the entire relationship worthless and completely disrespected by the other party.
I decided to go into a relationship because I loved my GF enough to be in that relationship. I'd rather not get into specifics as too why im in my relationship because I dont really feel comfortable talking about very personal things, but in general its because me and my partner both love each other.
And once again, i'd like to point out that I have never cheatd on my partner and never will cheat on her since she would be devstated by it. But her reasoning was based off of her own jealousy being extreme, and really that's not much a deal breaker for me when im obviously in love with the person