I was thinking about this last week after watching the South Park episode that featured Queer Eye for the Straight Guy.

Mr Garrison complaining that straight people are stealing gay culture by dressing well, taking better care of themselves and speaking in a stereotypical/ effeminate "gay voice".

I understand this is supposed to be "Metrosexual" (apart from the voice, possibly). The opposite of this is supposedly "retrosexual"

Retrosexual has the opposite problem as "Straight acting". It sounds needlessly denigrating towards those that DO identify with it. It's also supposed to apply specifically to straight men.

So... is there a less offensive term that refers specifically to gay men that identify with a hetero normative lifestyle?

It feels unreasonable to take offense with "straight acting" if you don't have an equivalently descriptive alternative.