You're right. I just love the interaction that we get to have with our companions. If he was an NPC of the [[GALLOWS | KEEP | GRAND CATHEDRAL | LOVE SHACK]] variety, I'd hope that he'd come to track the Inquisitor down himself somtimes. I'd hate to keep having to go to him myself to further a relationship. If that makes sense?
Agree! It would be nice to see your LI take a little initiative in the next game, Cullen included. 
Agreed on all of the above. However, I have wondered what you guys think - has he had previous relationships? Even if just casual in nature? He doesn't strike me as the casual sex type per say, but perhaps a more casual relationship of some kind with another Templar?
At the same time I'm not certain what the Tempar order itself is like. For example, the circle seems rather relaxed when it comes to the casual tryst in the corner - would the Templar's be similar in that they would 'look the other way'?
I always imagine he's had some kind of experience. It probably wasn't lasting, maybe went badly, maybe just didn't work out, but I can't see him going completely without. I've played with different ideas over the years. That being said, there's no indication of course one way or another, so who knows!
I'm not sure since some people say there is some that there isn't... however it seems like many templars don't follow the vow closely if there is one, so many templars went to bordels in DA2 and of cource some not so nice one's raped mages : / Anyways it seems like quite many templars had sex during the games.
DG has addressed this. There is no templar vow of chastity.