I recently went on several dates with a woman. To be clear, these were dates, in that I picked her up, paid, and was painfully charming. On our third date we kissed, but she pulled away and told me that she has a boyfriend. I was ... surprised. Later that night she texted me, apologized and told me that she was going through a "slow breakup." Should I give her some space and maybe try again in a few months? I really like her.
She is going through a slow breakup in the sense that everyone in a bad relationship is. That doesn't mean it's going to end any time soon. It's unfortunate that sometimes when people are unhappy, they use that as an excuse to hurt people like you who don't deserve it. Whether or not this girl is truly unhappy in her current relationship or, more likely, unhappy with herself, she is not an option for you right now. Which you seem to already know.
Think of it like you're giving her back her stuff, only it's Instagram. There is nothing like removing someone from your life to make you realize how much space they were taking up.
I know cheating is a cut and dry issue for most people, but I don't know, I can't really wrap my head around it. The lying and the deceit are decidedly bad traits in a person, no question. But we're all capable of being monsters if the situation is right. Speaking on someone who was once in a relationship with someone who was always finding new and exciting ways to sleep with anyone other than me, I mostly just feel sorry for him. Because he has to wake up every morning as himself, terrified of being close to someone and always worried that he might be found out. This is also after years of hating him.
It's up to you to say if this girl is worth pursuing down the road (in like, a year). Don't wait around, though.
My roommate told me that she thinks my boyfriend and I fight too much, and that maybe it's time to take a break. She is my best friend and has to hear about all of my silly little complaints about him. But I'm happy, so she's wrong, right?
So when you're in love, your brain releases endorphins into your bloodstream that tell your brain that it's totally fine that a grown man still has a Scarface poster in his bedroom, or whatever. Know that you aren't really an objective opinion on the subject of your relationship. At the same time, it's nobody's business, and you don't have to take any advice that is given to you on the subject. Including mine.
Your friend -- assuming she is a good one and this isn't some sort of Regina George situation -- cares about you and wants the best for you. She is hearing about your fights and complaints from you and maybe seeing some of it first hand and it doesn't sound like she likes it. I know that once I start really complaining about a significant other to friends, the end is near.