I think we're all 'assuming' your son is totally healthy , has a job etc and that he could be in his own apartment or whatever. If so then I agree with the others that its his choice to stay or not. But you mentioned he did not grow up with you being nude - so I can understand how he may feel this is now a weird situation- so I think its nice for you to weigh his opinion to some degree, especially if there are reasons unknown to us about why he's living at home - health wise or money wise or whatever. Also if he is helping pay the mortgage or rent etc- then he does have a bit of a say-so I suppose or at least a right to his opinion. But... still at the end of the day even if there are valid reasons why he is at home, it is still your choice assuming YOU own the home and paid for it. My 2 cents lol
He works full time but doesn't make enough to afford his own place. Could afford to share with a house mate. He covers his own expenses but doesn't pay rent.