Here are some brief thoughts on how you can show disinterest without looking like you're being overly reactive.
Just as there are different levels of showing interest and approval, there are different levels of disinterest and disapproval. "You're a bitch and a cock-tease" is a very strong one, and something like that's going to come across as pretty reactionary! Disinterest that makes you look bitter is out of proportion and shows that you're having an emotional reaction to her. So what can you do?
My all-time favorite one is to pull that little involuntary twitch of "oh, she messed up" that you'd use if she accidentally made a huge faux-pas. It's a really subtle expression, but we've all done it naturally in other situations. Simply reverse-engineer it and practice.
Be careful how you show disinterest, as you don't want to be getting back into a silly conversation or exaggerated teasing once you're at a certain part of the interaction, or you'd be moving backwards. I think, in practice, I'd most likely roll my eyes theatrically (definitely showing disapproval, but not reactionary).
Something else to consider here is the "hook." With this technique you embed something interesting in the conversation (i.e. "ha, that reminds me of the time I saved an orphan from sixteen marauding sharks..."), and then move on straightaway afterwards, rather than looking expectantly at the person for a response.
Some call this the 'throw and go' when it relates to teasing. Teasing 'expectantly' and woodenly is a common mistake guys make, without even realizing it, and it looks totally childish and reactionary. Teasing should be fun and light-hearted - one example I use a lot is "don't look at me like that, my mother looks at me like that!" It's not even mildly insulting, so it's hard to do it wrong (and with my tendency to drink heavily, that's important).