<human>: Let me start out with saying that this is one of the least significant problems in relationship history, in the grand scheme of things. 

I've been texting this absolutely groovy girl for about 2 months now. She goes to my college and we'll be back at the end of next week, where we'll be hopefully doing more hanging out and cuddling. 

She has this ex-boyfriend, who every time I post something on one of the selfies she posts has to say *something* to me. I'm worried that it might become a bigger issue if her and I start hanging out at school—seeing as he goes to school with us too. 

I'm a little dude and by no means a fighter, but I'm really vibing with this girl. I've had ideas about maybe sending him a Facebook message and just asking him to cool it and try and be friendly. I just don't know if there's anything to do with this situation or to just let it play out—that's why I've come here!

Can you summarize the given text in a few sentences?
<bot>: ex-boyf is trying to ruin the potential of a really awesome girl and I; is there anything I can/should do?