Busting your load on your partner in way that is amusing to you and/or your friends but not so much to your partner. It can involve anything from pulling out and busting a nut on her face/ear to such famed manuevers as the spiderman, superman or even the gorilla.
Erin wasn't too impressed when Shawn pulled an immature ejaculation and came on her nose.
Similar to premature ejaculation except male acts childish and throws a tantrum.
It was just an immature ejaculation all around, i mean he was throwing clothes across the room, yelling, crying; i must have been really drunk.