A couple were believed to be having sex in the open on Jomtien beach, located south of Pattaya.
The foreigners' "loud" intimacy was caught on video and shared on Facebook by Mr Denis Krungtep. He wrote: "Is this normal for Pattaya?"
The couple did not seem to care that there were onlookers, reported The Pattaya News.
Netizens have expressed shock and outrage over the behaviour, with many calling for the couple to be arrested.
The local authorities are investigating the incident.
This is not the first time in recent months that Thailand experiences uncouth behaviour by foreigners.
In a post shared in Facebook group Du Lịch Thái Lan on Jan 30, two men were spotted wearing only trunks and slippers at Phuket International Airport.
On Jan 14, two tourists sunbathed on the premises of Wat Chiang Man, a revered Buddhist temple in Chiang Mai.
And two tourists were warned by Phra Nakhon municipal police for sunbathing in bikinis at Sanam Luang, Bangkok, on Dec 29.
This article was first published in The New Paper. Permission required for reproduction.