Need help finding the perfect word

I won't go into details but theres a really good chance me and this girl can become no strings attatched fuck buddies. Shes been hinting at it and I want to ask her tommorow. I want to ask her formally though, so does anyone here know what the correct wording would be for this type of relationship. I know the opposite of this type of relationship is a "Platonic Relationship". Any help is appreciated

Ask her if she wants to join your Penis Club. That's what I call it.