Inserting into my sister who has never seen a raw penis, yet while thinking about SEX, she only masturbates. "I can't cum with my brother!" she says, but she loses control, has an orgasm, squirts, and trembles while arching her back, trying desperately to hold back her moans. It's obvious she's cumming just by looking at her. I'll keep pounding her until she honestly says, "I came." The beginning of piston SEX!
