Great news, glad to hear it

Thats awesome, and yes communication really is the basis of any good relationship, regardless as to the amount (or type) of sex thats being had.
Personally I still think bringing it up at the best time that you feel is right, while doing dishes, watching movie, going for a walk, any time you feel is right. Still, thats just my opinion for making it an easy yet careful conversation, so its not a 'we need to talk' sort of thing

That might put a little pressure on, rather than keeping it light & open. That way might not be so self conscious for them. For me, that would kinda be best approach, like a planned, non-confronting sneak attack

, so to speak.