The Belgian men, aged 29 and 32, stripped off and went for a dip at Ostia beach, Il Messaggero reported.
Rather than go for a swim, they allegedly chose to expose themselves to beachgoers and touch their genitals.
Their antics angered beachgoers who, on realizing the tourists were completely drunk, phoned the police. Officers arrived on the scene and caught up with the Belgians, taking them to the police station to report the two for obscene acts.
The men are not the only tourists to have got in trouble during their Italian holiday this summer. In Florence, a couple of Australians were caught having sex on a bench in full view of the public.
The incident came less than a year after two Americans were spotted having sex in front of the city's Chanel boutique.
During this year's July heatwave, tourists began splashing about in Rome's fountains to cool off. The famous Piazza Navona was a particular hotspot, with groups of Americans and Belgians both caught in the square's fountains.