Here's a of possibilities

Only a true whore would do this. Even the most immodest stripper has the common decency to cover her breasts with air.

I've done this experiment before but instead of outer space I just used what I had available.

The nipples get hard and the female makes noises.

Space isn't real

Have you seen those weird pornos where they vacuum pump a woman's breasts? Space has even better vacuum, so it will be like that, but worse.

Sunburn.

They'd likely get bigger, actually. Not much else, likely a bit of tissue damage, and then they'd freeze. They won't explode or anything.

Immediately, they'd just float. Longer term, they'd get very cold, but it takes a long time because there's nothing to conduct the heat. Some of it still radiates, is my understanding. So eventually, she'd freeze her tiddies off but just flash should be ok.

They freeze like the rest of humans

Nothing. You need a pressure differential for something to happen. Fat isn't stored under pressure and it's not sealed in like an eyeball.