Not trolling. I've seen my female friends do this many times/seen my male friends have to do this for their gfs/fiancees/etc. People have really different standards of what's acceptable based on a person's biological sex. Again, note that it's something that's not a given in gay relationships, because they don't usually follow heterosexual cultural scripts. I wish people would study it more because I think it's potentially a really interesting way to investigate heterosexual gender roles and norms.