a slang used to refer to the perineum, the part of the body between the anus and genital organs, overlying the pubococcygeal muscle. This term supposedly originates from the fact that, "'Tain't your balls, and 'tain't your ass," "'tain't" being a contraction of "it" and "ain't", in this case, meaning "it is not."
love you have for a person that is so deep and feels like it should last forever, but it can't for some complicated, unfair reason. So when you have only a certain amount time left with the person you love, you know that it is tainted love. because although you would risk your life for them and think of them all the time (even in your dreams), you can't be with them forever.
If you intentionally drool onto the girl taint while eating pussy, it lubricates the asshole beneath it potentially paving the way to slippery hot pot hole action for your flesh dildo.