I liked to imagine a couple of over nights during the trip involving both of them in a single tent (and soldiers trying to keep a straight face the next day.) Considering his propensity for kissing on the battlements in plain sight and sex in his office with unlocked doors, I don't see he'd really balk at that...
Well I think they didn't do that on the desk (I'd love to but I'm thinking about him taking ages to take off his armor haha, more like:"hey let's continue that upstairs, OK?") especially if there are all these soldiers coming and going through the office all the time. Cullen said he likes to keep his private life private, so I don't imagine him having sex just next to his men or with the risk of being disturbed in the middle of action, I guess he learned the lesson with the first kiss scene XD he wouldn't want that to happen again. He's a shy guy ^^ To my eyes the desk scene was their first time, but others might see that differently.
And the kisses in plain sight... It's just innocent kisses so that's différent

they don't do that in the middle of the hall

Well... Lothering is supposed to be in the arling of South Reach, so it's not that far away from Haven/Skyhold. Methinks that Cullen just doesn't want Mia to know where he is in order to prevent her visiting him and telling everyone embarrassing stories.
That would be funny
Sister:"When he was 6 he did pee in his bed, remember?"
Cullen: "Maker's breath, don't talk about that!"
No, South Reach is pretty far, since Haven and Skyhold are in the Frostbacks.


I don't have these two places just above Val-royeaux, what is it? In fact I don't have any of the small icons.