A third movie Idea: Three Men and a Young Lady
20 years later, Mary is a beautiful young woman, played by lets say.....,Keira Knightly...
Peter and Sylvia have been married for 20 years and Mary has several younger siblings.
The big news is that Mary is getting married. While facing the idea of their once little angelic little lady getting married, Peter also has to deal with his oldest daughter w/ Sylvia (younger than Mary), a teenage daughter named Kaitlin, becoming a young woman and going on her first date.
Yes, I know there are OTHER threads with third movie ideas, but this is my own idea, which is probably almost the same as the others, haha.