principal0 saidrunning11 and ohboy have it down. You should be sharing these feelings with your boyfriend instead of everyone here.
There is no "slutty phase" that universally happens among all gay men. You do not "need" one. Those are simply excuses for immaturity and lack of self-control, neither of which are great for any sort of adult undertaking, including having a relationship.
Oh, and you should keep in mind that there are some truly vindictive people out there. The consequences of cheating might be more than you bargain for. I think, before you allow yourself the liberty of violating his trust, you should make absolutely certain you clear the air on the matter for your own sake, if you don't have the integrity to consider his.
How prudish. You'll just end up a cheater eventually.
Eh, I think you have no basis to begin claiming you know what I will or won't do. It isn't as if I've lived without temptation, but I rose above it. I would sooner end a relationship than cheat.
I understand that people fall in and out of love. I understand that sometimes, while we are in a relationship, we make a connection with someone else that we cannot deny. However when there is a change in your feelings, it is incumbent upon you to express those changes before acting.
That's really not much of a restriction - it simply means you must agree to consider the other person, and be willing to have difficult but honest conversations. Being in a relationship, to me, means you can't be a moral coward.