The 29-year-old star was seen soaking up the sun in the city when Koma joined in on the fun as the couple celebrated a lovey-dovey holiday by the beach, reported E! Online.
Wearing a two-piece white bikini, Duff was all smiles while cooling down in the ocean water with the music producer.
The duo was also spotted exchanging a few kisses with as Koma helped carry her in the water.
Duff even took to Snapchat to share a couple's shot as they enjoyed a drink from a coconut.