The girl group - who shot to fame in 2008 with 'If This Is Love' - want to outshine the lavish eight-day stag party thrown by the JLS boys for Rochelle's fiance Marvin Humes.
Speaking on UK TV show 'This Morning', Irish beauty Una Healy exclaimed: ''Wait for our hen ... we're going to go wild!''
While Marvin partied in Las Vegas with his friends and bandmates - Oritse Williams, JB Gill and Aston Merrygold - to celebrate his last few months of bachelorhood, Rochelle was at home cooking for his family.
The 23-year-old singer laughed: ''It looked like he was having a whale of a time. He was handcuffed to a dwarf, he went in a helicopter, he was in the casino 24/7, he wore a bikini ... I was with my new in-laws cooking.''
Discussing her own fiance Ben Foden's scandalous stag do, on which the England rugby star was photographed naked in a strip club, 30-year-old Una said: ''We all have to see what our fiances do. For most people what goes on stag stays on stag, whereas we get to see it all. It becomes a bit embarrassing and all that but it's all behind us now.''