I asked her to spit on the lid of my drink, and she watched as I licked it up and told me I was a good boy lol
You could always ask about her piss. A different barista stuck a straw up her pussy and gave it to me and also let me touch her tits. Unfortunately, this girl isn't working anymore.
Just be respectful. Always ask what they're comfortable with and don't pressure them into doing anything they don't want to. You'll get farther with them that way.