School's out for the summer, but Sadie Spencer still has a few lessons for us. And we're her eager-to-learn pupils. Sadie's lesson plans include anatomy, sexuality and boob-ology.

"I'm pretty much obsessed with sex and sexuality," Sadie said. "Everyone has different buttons, you know? Things that get them hot and things that turn them on. I like exploring those things and learning what makes someone tick."

What turns us on and makes us tick here at XLGirls is sexy girls with huge tits. And Sadie is well-acquainted with boob-obsessed men.

"You mean just about every guy?" Sadie responded when asked how often guys check out her rack. "It's basically all day. Of course, I do wear outfits that accentuate my tits. If a girl has it, why shouldn't she flaunt it?"