Your hippie girlfriend thinks that monogamy is a drag. She wants to invite another person into your bedroom to share the love. How about your best friend? She does a striptease to get both of you hard, then takes one of you in her pussy and the other down her throat, switching which holes you're using when she changes positions. After having an intense orgasm of her own, she challenges herself to suck both of you off at once, encouraging you and your best friend to cum down her throat at the same time.