Well you're on a college campus, as they have said: women abound. Short of a gynecologist's office, you're unlikely to find a higher female:male ratio. In class just be like "Hey, can I borrow your notes from last lecture? I wasn't here." Then when she says "You were so here; you sat right beside me. Just like today." You can say "Next time maybe I can sit
inside you.
". Let us know how it goes. ^_^