Tony is indeed an all around actor- he can also do great comedy which is not easy to do. Some people are born with a natural talent and Tony is one of those. And now that he has honed this talent to perfection, it is a delight to watch him.

Also his character in the film goes through some sort of a transformation. There is a huge difference between their first and last sexual acts and Tony manages to convey this with just his looks. Actually I saw this film twice in one week and think that Tony's performance is flawless.

He has the balls alright.

If you want to see Tony as a baddie check out The Longest Nite (very good film, and not just because of Tony)
I also think Tony is a kind of baddie in Happy Together but I'm alone in feeling this way.

As for the nudity we get to see his balls -and I was very interested- plus some part of frontal nudity but more importantly it really looked like they really were having sex. It wasn't like he is half a meter away from her and we just see his ass. Ang Lee is really good in determining what to hide and what to show.