It sounds like she herself is a little confused, I think the whole "strictly platonic" thing may just be something she's telling herself so she doesn't feel like a slut. But like always, actions speak louder than words. If she keeps saying she wants to stay friends but yet drags you to her place then she obviously is not that serious about staying just friends.

Regardless, stay keep going for the f-close and show that you're beginning to lose interest if she really does start to friend zone you. And if she's a cool girl who's fun to be around then it's like you said, 'friendship' with a little bit of sex thrown in every once in a while isn't too bad.

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