in too deep

I met this guy on tinder and we've been talking for a few weeks now. We had dinner one night and afterwards I told him I wasn't looking for anything serious and he wasn't either so we decided to keep things casual. 

We hooked up a few times and I've started to gain major feelings for this guy. I've had multiple relationships with guys like this but I've never caught feelings. 

I did some social media digging and found out he may still be with his girlfriend that is in the peace corps oversees so I'm afraid he's just using me. 

I haven't talked to him about any of this but I don't know how to bring any of it up. 

I'm worried that I should probably just loose all connection with him to protect my feelings but I really like this guy and I don't know what to do.