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

>>17
I do like her, I wouldnt mind going steady with her, but if i tell her that, she'd probably get freaked out at this point and i'd be left with no ass to fill up. So if things do escalate to something else from here, its all good.