How do I get my girlfriend to stop dressing me as a girl?

This is a very weird situation, but I have an older girlfriend, kind of a sugar mommy-type thing I guess. She lives cosplay and we go to conventions a lot. She would dress me up, do my make-up and stuff and it was fun, I didn't mind it.
But now she's start of doing it just for going out normally, she'll have all kinds of different dresses, wigs, etc for me and I feel like I can't say no.
The other day she was calling me her "girlfriend" and asking if I preferred skirts or shorts for going out casually, I'm getting a bit worried.

Is there a way to get her to stop without breaking up? Pics included for context I guess
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
How do I get my girlfriend to stop dressing me as a girl?
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