you have the right to not trust him because you've been hurt. that's natural, but you should go with you're first mind. if these "friends" are "just friends" then maybe you should suggest inviting them over to observe how they act towards eachother. or just simply bring up the idea of meeting one of his "friends" and see how he acts. if there are discrepancies, then there are problems. without trust, you have nothing. so do wat i've suggested and see how he acts, and you'll know by his reaction. if they're secrets, then they're not friends.