Age difference a problem?

Baylee

So lately it’s been stuck in my head and I can’t seem to let it go. I’m 18 and he’s 20 about to turn 21. All that’s been on my head is “he’s going to go clubbing and bar hopping and I won’t be able to go. He will surely want to find someone that he can do those things with. So I bring it up to him that it’s been bothering me and his reply was “I’m not really thinking about that right now” and “Is something wrong?” I guess I’m just getting down about it. I don’t want to hold him back from being young and experiencing all of those things, but I also fear losing him due to our age difference? Any opinions ladies?