The series ended after a turbulent 12 season run . Many thought Charlie Rose would make an appearance . Seemingly every character in the show 's history -- and many exes , including one who was sleeping with John Stamos -- showed up as Alan and Walden tried to make amends on what they thought might be their last day alive . Sheen said he would never appear on the show again .
The series ended after a turbulent 12 season run . Many thought Charlie Rose would make an appearance . Sheen said he would never appear on the show again .