Alright, you've pretty much exhausted your collection at this point and there's only one place left to try; the arcade! She might be able to stomach the smell of spilled soda and body odor that flows through the place, but if you see Boong-Ga Boong-Ga anywhere on the floor, promptly make a dash for the front door before she plays it.
Playing the game requires you to literally slap a giant prosthetic ass before trying to jam your fingers right up the crack. You can select a variety of avatars to assault, with the goal being to cause them as much discomfort as possible. Do well enough and you'll get a small plastic trophy that looks like shit.
Oh yeah, one of the avatars is "Mother-In-Law", so tread carefully.