somebody who has adopted you, somebody your mom had you with, someone you love, etc. sometimes they are someone your mom doesn't love. they are called baby daddies.
In male prisons, a prisoner who is always the pitcher, man or top, i.e. the penetrator or recipient of fellatio, in same-sex relations with a prisoner who is the catcher, girl or boy, i.e. the penetrated or fellator.
Mark was a notorious daddy in San Quentin. He was runnin up in and gettin head off all the young dudes coming in.