The rules of the "Truth or Dare"-themed game are simple: Each contestant gets to choose between answering an incredibly revealing question about themselves or their work, or eat some downright disgusting items like cow intestines, bull penis, sausage juice and a sardine smoothie.
The Aerosmith frontman came prepared for the disgusting delicacies, bringing his own knife and fork -- as well as salt and pepper -- to season whatever nasty treat that came his way. The first question for Steven: "As a rockstar your life is all about excess. How much have you spent on drugs in your lifetime?"
"About 2 million dollars," he quickly replied. "I snorted half of Peru. Ask anybody that's gonna be honest with you!"
Steven then asked James a question he was not willing to answer: How much did he get paid to do a private Carpool Karaoke from someone who shelled out big bucks for a birthday gift? Instead of replying, he downed a shot of Vienna sausage juice and instantly regretted it, spitting it back up in a bucket placed beside him.
Tyler ended up downing some cow intestines when his next turn came, as he refused to rank all the other members of Aerosmith, "in order of talent." Like Corden before him, it also had him reaching for his barf bucket.
It was then time for some major tea, as Corden sidestepped chewing on some pig head jelly by revealing the guest who was "so annoyed they walked off the show."
"There's only one person. It wasn't the show. I kinda understand it, I get it and I hold no grudge. What happened was, for the anniversary of 'Back to the Future,' we were going to do a best of the '80s Carpool Karaoke," he explained, adding they had gotten a DeLorean for the shoot. "And we booked Bryan Adams to come and do the thing, I love Bryan Adams, he's terrific. I don't know that Brian's management had told Bryan that it was a sort of collaboration with lots of other singers form that time period. So Bryan came in, seen the list of other people that have done it, got in the car and left. He just bolted, he was gone."
The juicy reveals kept coming with Tyler's final turn, as Corden asked if he's ever hit on one of daughter Liv Tyler's movie star friends.
"Why yes I have. And I got a lot of shit for it too," he explained. "I was at Stella McCartney's party, of course I went with Liv. We left and all jumped in a van and who would be sitting to my right? Cameron Diaz. So I look at this beautiful woman and say, Cameron, should you ever need someone to take you to the movies or like if I was to ask you to show me around London ... and of course Liv went, 'Daddy, you're hitting on my best girlfriend!"
Tyler said he "felt ashamed" ... but only for a moment. See more "Spill Your Guts or Fill Your Guts" videos below!