Published Monday, 24 September 2012
The reality TV star proposed to girlfriend Lisa Stelly last year and they became first-time parents to daughter Pearl in April.
The 26-year-old revealed in June he had been diagnosed with multiple sclerosis, but insisted he was focusing on his nuptials to take his mind off his health scare - and now it appears the wedding is approaching.
In a post on his Twitter page on Saturday, Osbourne writes: "Let the games begin! Palazzo (hotel) Las Vegas bachelor party."
Stelly also uploaded photographs from her bachelorette bash showing her in a burlesque costume, complete with a white bobbed wig and matching feather boa.
The bride-to-be revealed her fiance's sister Kelly had given her a saucy gift: "Thanks Miss Kelly O for my diamond encrusted riding crop. I'm obsessed with it, I can't put it down."
She also poked fun at her partner's celebrations, adding: "My bachelorette party is better than your bachelor party Mr Jack O. Best party ever! Woo hoo!"
Osbourne replied by posting a picture of himself wearing a casual outfit and baseball cap alongside the caption, "Well wife to be... I think mine is about to get a whole lot crazier then yours."