<human>: Backstory, my roomate is one of my best friends. She met me in high school and we've been friends since. We tried going out, nothing really clicked and we both decided friends is a better status. We don't have any feelings for eachother. I have another friend from throughout school(m20) who is now going out with her.

My friend throughout school is known for being a bit manipulative, has hurt himself because he has upset his previous girlfriends, has hurt others for going near his girlfriends (not even for anything worthwhile, just friendly encounters.). and I don't see him getting better without any professional help. 

They have been going out now, for almost 7 months. She is trying to maintain the relationship but puts far more effort into it than he does. He tends to mooch off of her (borrows money often totalling to easily over 100 dollars.). He has used her car despite it being inconvenient for her. He's skipped work to go to a carnival while she worked despite obviously needing the money he would have made (borrowed 10 from me there.). He's been blowing her off VERY OFTEN to play dungeons and dragons recently. He's also cheated on her through texts that she innocently read, (she was looking for her own conversation to check if messages went through.).As you can tell, the list goes on and on. But she still loves him (her words, she's next to me.)

I'm trying my best to be fair to her and get as little biased advice as possible for her. She has done nothing but be loving and caring for him, but gets little back nonreciprocating(idk if that's the right word.). I want her to be happy but his best efforts are typically, "aww babe, you know how cute you are? Let's have sex." (not far from what would actually be said.) I don't want her to be used for sex.

Can you guys help? 
Feel free to ask any questions, we'll answer them.

Can you give me the gist of the text in a nutshell?
<bot>: Best friend(f19) is going out with kinda ex friend(m20) and he treats her like garbage.