<human>: My current boyfriend that I have been with for 4-ish months now is making me doubt my trust in him. We started talking on Tinder (of all the places!) in February, this year while he and his ex (who he lived with) were on a break. During their break we really hit it off, he's a med student and I'm a vet student so we had a lot of interesting discussions and similar interests. Although, after a month of talking he got back together with his ex again. He explained to me that he wanted to try to make things work with her which, at the time I could understand so, we deleted each other from any social media etc. 
After a week or so he added me back on snapchat and began being flirty with me but would delete me most nights just to re-add me in the morning (obviously during the time he was with his ex he would delete me) 
To cut a long story short, she found out he was doing this, it ended and now we're together. He says he's happy that we are together and that the reason he kept in touch with me was because he wasn't happy in the relationship and wanted to be with me. 

However, my problem is that he is overly protective of his phone. I'm aware he talks to girls that I don't really know, mainly through snapchat that he claims are just friends. 
He has a history of being unfaithful that he will openly talk about. 
He constantly comments on other girls appearances (how hot they are etc) 

I feel as though I'm fairly laid back but I feel as though I don't fully trust him yet. 

Any advise is appreciated!

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: we got together when he was technically still with his ex. He's protective over his phone. He has a history of cheating. He comments on girls looks frequently.