I haven't read the books since around when AFFC came out, but as I recall, that scene played out almost exactly like it did in the books. Drogo wasn't really being forceful (well, I guess he pretty much was by modern standards, but considering the medieval setting not so much?) but he was still going to do it whether she wanted to or not; it was pretty clear that she didn't. Also at least she's not 13 or whatever like she is in the books...