Well if I consider Sebastians too hard I doubt I'd like BG2 style one's then at all :3
BG2's ones had a lot of ways you could mess the romance up by choosing the wrong dialogue options (the romances were based entirely around picking the right options when talking to them , there was no "approval" mechanic), and they weren't marked as such (there's no heart and broken heart symbols) - most of the time it was reasonably obvious what option to chose to continue the romance, but every now and then it would throw a curveball at you. For example, IIRC, the first two times Viconia wants to have sex with you, you have to accept, but the third time you have to turn her down, else you end up as friends with benefits and nothing more. That's not to say there's nothing at all to suggest that you should take that option, but it come in the form of her overall story and character, rather than a clear indicator when the dialogue comes up (i.e. you, the player, have to think a bit, and come to the conclusion that, if you want her to actually fall in love with you, you're going to have to show her there's more to intimacy than simply banging every night).