We have... "gooner" cup guy.

We have a regular who keeps bringing in what we all started calling the "gooner" cup. its just covered in really sexual anime girl stickers. like, full on biddies on the cup and i... dont know what to do about it? hes otherwise very normal, he never makes inappropriate comments about the baristas, he doesnt try to flirt with any of us, hes always very polite, but its so awkward putting that iced caramel macchiato with extra whip into that cup. especially because we do have a few minors who work at our store.