The 31-year-old actress explained on Thursday's Jimmy Kimmel Live! that her and her husband John Krasinski had decided to do something crazy for Matt Damon's birthday and invited Cruise, 51, to come along. "I don't know if you've heard of this club called The Box. It's kind of like a burlesque ...sex club. ...There's weird things that go on and make you cringe."
"Earlier, I think he thought it was going to be a nice, civilized dinner," Blunt recalled. "So, I emailed him and I was like, 'Tom, change of plan. Um, we're now gonna go to this club called The Box. Just wanted you to know, you may not be comfortable with this. It's kind of like a sex club.'"
Cruise's responded, "He emailed back and went, 'Jesus Christ! Well just don't let me walk out of there alone!' which we didn't."
In addition to her "sex club" story, Blunt also opened up about her newborn baby Hazel.