The boyband are currently in the city for Marvin Humes's stag do celebrations, having arrived in the US last week.
Aston Merrygold and JB Gill were photographed by a swimming pool, with a champagne cooler of what appeared to be condoms featuring Humes's face on the box positioned between them, reports The Sun.
Humes was previously spotted handcuffed to a dwarf named 5 Cent when they first arrived in Las Vegas.
JLS launched their own Durex condom range in 2010.
The 'Everybody in Love' stars were recently said to be concerned with rival boyband One Direction's huge worldwide success.
Watch the video for 'She Makes Me Wanna' by JLS below: