I also don't see what the problem would be for him to propose after the wedding. Right before or the day of, obviously is different and I can see how that might be stealing some of your thunder, that time is about you and your FI. But after the wedding, at least at mine, everyone did their own thing, that was their vacation time. I was actually hoping my friend's bf of 4.5 years would propose during that time. I know she was secretly hoping it would happen, so I would have been really happy for them if it had. But, everyone is different and I don't think everyone will come to an agreement on this subject. I think if it means that much to you then have your FI talk to his friend about seeing if it would be ok for him to wait till after the wedding.