ET caught up with Blake Shelton ahead of Tuesday night's live episode of The Voice, where the 39-year-old country singer extended an invite to his girlfriend and fellow coach on The Voice, Gwen Stefani, to attend the big day, along with her kids.
"If she wants to bring the boys out there, that's awesome!" Blake told ET, smiling.
"You know what? I made a vow to myself that I was going to be just completely immature without the help of anything else," Shelton joked. "Just a big glass full of slime. [I'll] do a little shot of green slime and I'll be ready!"