The Oscar winner was enjoying a dip in the Mediterranean Sea with his girlfriend, Vittoria Ceretti, as they jetted around the crystal blue water in goggles. Yet, the fun times didn't last long, as Leo soon emerged from the water ... and called out for help regarding a mark just below his tush.

Clearly suffering from a jellyfish sting or a bite of some sort, Leo hopped beneath the yacht's outdoor shower ... where his model girlfriend took a closer look at the wound.

The yacht's crew rallied to treat the actor's injury, as they sprayed it clean and dried it with a towel. Thankfully, the sting didn't appear to be too serious ... as Leo was photographed sharing a chuckle with his lady over the situation.

It would likely take a lot more than a little tussle with a jellyfish to ruin LD's vacation. The A-lister is currently abroad with several of his celebrity friends, including Tobey Maguire, Lukas Haas, Edward Enninful and Neelam Gill.

Leo and Vittoria have been making the most of their time abroad, as the couple enjoyed some sun in Portofino earlier in their getaway.

Their relationship, which first kicked off last summer, appears to be going strong ... as the duo have been inseparable of late.