Ah, you're in the honeymoon phase.
I hope you guys continue being discreet, because you are right - for now it's the best thing. You'll know when you're ready to make every thing public.

I've known many who have done this and have married their mates. For some, it can get ugly if there is a break-up and can make things uncomfortable. I think every person has done this at one time or another.

Just be careful. And have him meet your friends. They tend to take the blinders off.

Good luck!