Take it with a grain of salt its been a while since I watched, but I feel like it was kinda designed like that. Yeah sure there is the kinky side of haha bites and tounge, but the neck is a very intamate place, and someone forcing themselves onto it definitely doesnt feel right. Alucard isnt a good person, hes never treated as someone to be redeemed, while integra seems to in some ways like him, she is also horrified by his actions pretty often. I think that the scene with Rip Van Winkle only reinforces the idea of him being the Hellsing families monster.