Marvin Humes was left red-faced after 300 packets of condoms with his face on were taken on his stag do.
The JLS singer is currently celebrating his last weeks of freedom with a nine-day trip to Las Vegas before he ties the knot with The Saturdays singer Rochelle Wiseman and his friends and bandmates are doing their best to embarrass him in the gambling city.
Bandmate Aston Merrygold took 300 of Marvin's brand of the group's condom range for Durex and is handing them out wherever they go.
A source said: ''He ordered a job lot to hand out in bars and give to girls for a laugh. All the packets have Marv's face on them.
''He was a bit embarrassed when a neighbour had to collect them for him, though. It was hard to explain why 3000 condoms had come through the door.''
As well as ordering the condoms, the group - which also includes Marvin's other bandmates Oritse Williams and J.B. Gill - making sure everyone has fun by hiring a party bus to take them everywhere they want to go.
The source added: ''They've hired a party bus and it's absolutely full of beer and crates of vodka.''
They also chained Marvin, 27, to a dwarf for the day, who greeted him at the hotel lobby by saying: You're my bitch now! And you'll do as I say.''
After the all-day and night session, the dwarf - who goes by the name of 5 Cent - said: ''They treated me real nice.''