Mother & Son-in- law Dance?

Ladies & Gents, I could really use your help! FH tells me at dinner tonight that since he's not inviting his mom he wants to do a mother/son dance with mine. (Super sweet!) However, neither of us can come up with a good song! He thinks the classic mother son songs are too over played, or mention a biological relation between the two, which he's worried would sound weird. Any recommendations for mother/son-in-law songs are greatly appreciated! Thanks!