The 40-year-old star said he doesn't like to take part in the intimate scenes in front of a camera.
Speaking about the scenes on the BBC's The Graham Norton Show, he said: 'I don't like them very much. They are awkward because it is a strange and bizarre thing to be doing.
'It's not a normal situation, I am 40 now, and the actresses get younger and younger.'
He added that he always hopes that the scenes are done tastefully.
McGregor said: 'I don't like gratuitous, Hollywood type, sweaty sex scenes - they are embarrassing to watch and do.'