I'm not sure what the fascination is with seeing other people's moms naked, but I'm betting that Justin Bieber's momma Pattie Mallette (left) is going to turn down Playboy's $50,000 offer to pose topless. Her son's just turned into a veritable money cornucopia. Now that she's helped him sky-rocket to fame, she doesn't need a measly 50K or the inevitable shame it would cause her teenage son. But this did get us thinking about some other celebrity moms who might want to consider posing for Playboy.