A person's soul song is a song that they've never heard before, but when it comes on the radio (or is played in some other manner) they immediately know all the words.
Money in the Bank is Sam's soul song. She totally knew all the words even though she's never heard it before!
When a gay guy and a lesbian are best friends and they go on a double date with another gay guy and lesbian who are best friends. (Obviously the guys are dating each other and the girls are dating each other.)
Mark and Adrianna were polyhomocourting with Dave and Abigail.