He took to his Instagram Stories, where he shared a sweet photo of bikini-clad model Poppy Delevingne.
In the snapshot, the beautiful blonde smiled as she enjoyed a beverage from what appeared to be a hollowed-out mango, closing her eyes in bliss.
Poppy looked stunning in a blue strapless bikini, with her long wavy locks tied in a loose topknot. While the royal didn’t caption the image, wherever the pair is staying looks beautiful, with a flowerbed of bright pink flowers acting as a backdrop to Poppy’s pose.
Constantine and the model haven’t previously publicly acknowledged their relationship, although they were photographed holding hands and snuggling together in London last month.
Poppy, 36, is believed to have separated from her husband James Cook last year when she stopped wearing her wedding ring. The pair married in a lavish ceremony back in 2014, with Poppy’s sisters Cara and Chloe among her bridesmaids.
The Greek royal family has traditionally been very close to the British royal family, so much so that Constantine, 24, who goes by Tino, is Prince William’s godson.