Revulsion for Homosexuality: Learned or Inherent Behavior?

I used to think that tolerating homosexuality made me pretty broad-minded.  By tolerance I mean not being hateful to gays, or unkind, or trying to get them fired from their jobs, or making them social outcasts.  My position was this:  I am in favor of tolerance of gays, as long as I don't have to watch gay behavior or think about it.  To each his own, live and let live.

However, militant gays find my position unacceptable.  Tolerance is no longer good enough.  They want homosexuality to be viewed as normal and as natural as heterosexuality; they want full social and cultural acceptance.  They want a guy marrying another guy to be as unremarkable as a guy marrying a blonde or a redhead.  Is this even possible?

I suppose the real question is this:  is heterosexual revulsion to homosexuality learned or inherent behavior?  Is it even possible for militant gays to achieve their goal of complete and unreserved acceptance of their lifestyle?

I googled this question on the web and found little to support either position.  If anyone knows of any studies along these lines, please so inform me.  Whatever the truth is, let it be revealed.