We share, he has his, i have mine, it's not a big deal. We don't have alot of friends, but rather a small close circle. I've met people through him and he's met people through me . . .
It's not a big deal unless you really don't like to share and/or he is spending more time with your friends instead of with you? Sharing friends can bring up jealously issues, that happens allot.
Talk to him about how you feel . . . if it bothers you, let him know in a gentle way now before it turns into an actual issue.
honesty = good thing.
Sweetpea