The 34-year-old comic star - who is set to marry Katy Perry in the autumn - says watching the pair of singers gyrate erotically for him would be the perfect end to bachelorhood.
He explained: "I'm gonna get Lady GaGa and Taylor Swift to perform a lesbian show on my lap."
But in a bizarre twist to his fantasy, he added to the Daily Mirror newspaper: "I'm gonna shrink them down till they're the size of dollies."
The 'Get Him to the Greek' star - who proposed to Katy in December after a three-month whirlwind romance - recently revealed the party will have a Robin Hood-theme.
He wants to play the lead role with his best pals being the "merry men" at the bash.
Russell – who is now teetotal after overcoming problems with alcohol and drugs - explained: "I'll do adventurous things and activities. My friend who is my best man says we're going to go white-water rafting and shoot arrows.
"We'll be like merry men. Perhaps we'll become outlaws, bandits for a while."
The former lothario also insisted he isn't worried about the best man speech his manager Nick Linnen will deliver on the big day.
He said: "I'm not worried about the best man speech - that's for Nick to worry about. He's got to do it.
"Nick has stopped me from doing some seriously stupid things in my life, which could have made it a lot worse. I trust him completely. There isn't much more he can say that people don't know about. I took drugs and I slept with prostitutes."