The ending
When Daphne (or Jerry) trying to explain that they can't get married and finally reveal he's actually a man I though there is going to be a dissapointed/angry scene from Osgood but it turn out really funny. It's because I also though that back then all of the old people is homophobic and gay stuff is kinda 'sensitive'.
I goes 'awww' when he said well nobody's perfect because the guy who played Osgood looks like a sweet old man