I don't want to offend anyone, but... (proceeds to offend)😂....
If you want a sweet you can have an ice cream or a cake... coffee is what it is, and its taste is best appreciated without any sugar!
I would call them Traitors of the Natural Flavour of Coffee. Or perhaps, capricious/damaged taste buds.

🤣🤣

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Source: https://www.pexels.com/es-es/foto/muneca-con-anteojos-160472/