The tattoo reads, "mille tendresse" -- which translated means "a thousand tendernesses." It's actually from "Breakfast at Tiffany's," when Audrey Hepburn's character blurts out, "Bless you, darling Fred. Please forgive the other night. You were an angel about the whole thing. Mille tendresse."
Here's the thing ... it was actually Pete who made the tattoo matching, because Ariana got hers back in 2014. Both tats are on the back of their necks.
BTW ... that's not the only tat that binds the engaged couple. Davidson showed off a new tattoo this week of a baby pig he and Ariana adopted.