I wouldn't rush into anything based on just one problem (not that i'm trivialising it or anything), but if you haven't talked to him about it, he hasn't had chance to address the problem... he probably doesnt even know that there is one! (men, pah) also, maybe you could ask him not to text you at all when you're out with your friends, you may find that you miss his attention. otherwise, reassure him that you love him etc, because he's probably only texting so much because a) you're out without him so he misses you, or b) he needs reassurance that you won't stray.
why don't you take him out a few times with your usual croud of lads, so he can see for himself that there's no funny business going on?
hope this helps! sam xxxx