1. The action of a MILF becoming unattractive due to menopause.
2. The action of a MILF transforming into a GILF with use of a ThunderStone at level 30.
Stoned Guy "I wonder if Peters mom is still a MILF?"
Other Guy "Dude, MILFS don't just UNMILFITIZE that quick. Read a damn book, its common knowledge bro."