Paris Hilton has been dating 21-year-old Spanish model River Viiperi for a few months now, and this weekend their relationship went to a whole new level: They wore matching outfits to the pool.

The blonde was spotted in a one-piece, one-shoulder swimsuit and matching coverup at their Miami hotel Saturday. Her muscular beau wore a hoodie in the same print. Unfortunately, his swim trunks did not match (instead they were from Hollister Co.) and he opted out of wearing a floppy sunhat like Hilton and wore a baseball cap instead.

When a fan commented on their "amazing" matching outfits on Twitter, Hilton responded with "#Twins" and a winking face. Clearly, their coordinating ensembles were well planned, and not the result of something like, uh, losing a bet.

The pair have been soaking up the sun and lounging by the water by day, then attending clubs and Art Basel events by night. Oh, and both have been sure to keep their online followers abreast of all of their fun. Hilton tweeted Saturday that she wished she could be in Las Vegas to see the Manny Pacquiao fight, however, she settled for partying with Tiesto and her friends and siblings at LIV Miami.