Just wanted to remind you all of a relatively minor spoiler from Dragon Age Origins - Morrigan jumps in bed with you really early on. Just wanted to put it out there
Leliana also wants the Player Character the very moment she sees you
I haven't romanced either and I haven't even got flirting from them. It was always player-initiated. Only Zevran was generally dirty-minded, but it was just one character that was characterized this way. (And I'm not even sure he acted flirty towards the PC unless romanced).
