I think it was continuous shagging after TIP/TSP, but as long as there was at least the one time ... LOL!

If they were sleeping together then it makes it harder to suggest that he gave her up in JE because he’d decided he couldn't give her what she wanted. If you see what I mean.

No, not really, but again, I'm one of those who totally buys TenII as the Doctor and believes that the Doctor sees TenII as the Doctor too and therefore knows that she's still shagging the same dude ... in a weird, Time-Lordy-way.