A grandpa boner is a dirty filthy, fat, ugly often bald old man of 60 years of age or older typically found in south east Asia with a late teens to early twenties Asian escort with him.
Gross, look at that grandpa boner over there with that 17 year old girl. He has to be at least triple her age, triple her weight and triple her dimensions in every direction.
by BorisSDT August 25, 2011