A d1 baby is when to extremely athletic people have a kid(s) that will be an amazing athlete, supposedly better than both their parents.
Boy: See Amy over there? She's never missed a basket
Boy 2: Are you sure bro?
Boy: We could have the best d1 baby together dude!
Boy 2: I dont know man. D1 babies are like, the superior to all babies, can you commit?
The smooth-brained offspring of two P.E. majors is code-named D1 because it will bring home report cards marked with D for every class except one.
After fathering a D1 baby with Theresa, Mark got a vasectomy because the risk of having another one in a world already overpopulated with abnormally strong morons was too great.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi