My sister-in-law is getting married in a few months. No one in the family has really gotten to know her fiance very well; they've been together for about a year, and he's somewhat reserved and difficult to get to open up. Anyway, as the family's resident practical jokester, I'm looking for a funny but not potentially disastrous joke or something that I can pull off, just to sort of break the ice and welcome him to the clan. Someone has suggested the 'women in the audience with John Doe's apartment keys, please return them now' speech for the wedding reception, but I don't think that's a good idea. Suggestions? Thanks.