I used to work at Starbucks and we'd make weird shit out of curiosity. The best one was uncut cold brew coffee and their strawberry refresher base. Uncut cold brew and lemonade wasn't terrible but way too acidic for my liking.
Agreed! I'm also grossed out by the people who would get the Passion tea (which is made with hibiscus and lemongrass, and is very acidic) with heavy cream. It curdled damn near instantly and was just.... nasty.