Is my bf cheating or just insecure? Men HELP!?

Is my bf cheating or just insecure? GUYS HELP!?
so my bf and I have been dating for almost 2 years now and we live together now. He is very insecure about the way he looks. He is kind of a computer nerdy guy and I am just starting my modeling career. But he is always insecure because he thinks I am better looking. I am with 100% because i truly love him. A few days ago I found these emails in his yahoo account. Read below.

Nikki sent you a message.
Re: Hey

"so how many girlfriends do you have? there are alot in ur pictures. and how many random girls u found on facebook are you talking to other than me? no offence I just know how guys are"

Rebecca sent you a message.
Re: Hey

"4**-***9 :) well lets see where
this goes then"

Rebecca sent you a message.
Re: Hey

"hang out? lol how do we do that?"

Believe
Amanda sent you a message.
Re: Hey

"well i dont really know you and im getting to know you its not that i dont think you are cute but beauty is only skin deep."

Nikki sent you a message
Re: Hey

8901 bellow drive, cant go anywhere for a few days though"

Nikki sent you a message.
Re: Hey

"ya, good luck… lol. nobody likes to come pick me up, my house is hard to find"

Amanda sent you a message.
Re: Hey

"thats cool.. you think im pretty?? ha i dont

Ok so i don't know if he is talking with these girls because he is insecure and he wants to make himself feel better or what! I know he has never met up with them because i live and work him and he never goes out without me. So guys…please help me understand! Is he looking for a different girl???