When Astarion made his initial vampiric move on my dwarf, there was no sign on the PC in the scene until I elbowed him.
All I saw was the top of the bedroll, and it looked like Astarion was about to start drinking from the pillow. Obviously this is a height issue when characters are laid on the bedrolls - I noticed that several scene show the dwarf PC down in the bed and not with her head on the pillow. I haven't played through with a halfling yet, but I imagine there may be a similar problem.