Personally I don't feel Santana counts as "sex positive." To me, sex positivity is about acknowledging and embracing all different kinds of sexualities: straight/queer, kinky/vanilla, mono/poly, active/chaste, sexual/asexual... It's also about sex education, safer sex, enthusiastic consent, etc etc. It's not about flippantly declaring that everyone should put out, or pressuring someone to have sex because it's tiring to look at virgins, and it's definitely not about never saying no.

I feel like Santana has a lot of issues around sex, and a lot of that has to do with her discomfort with being queer. I'm still not entirely certain whether she's attracted to men, but it seems clear that she has had sex for lots of reasons that have nothing to do with attraction or sexual fulfilment, things like status and popularity and manipulating people. Not that it's necessarily bad to have sex for those reasons. It just seems like she wasn't coming at it from a sex positive perspective.