It's from the Golden Girls, believe it or not:

Blanche, Dorothy, and Rose are discussing something that's "a shame."
Rose: You know what’s also a shame?
Dorothy: What?
Rose: When you sit down and your thighs become twice their size, that’s a shame.

Looking at my peeping socks (see PPL thread) reminded me of this *other* reason I sometimes feel like I need to run home and swap out my pants...