The actor wished Kutcher well when the Just Married star was hired to join the cast of the sitcom after producers fired Sheen last spring (11), but it appears all that goodwill has changed.
Calling in to internet news show TMZ Live on Thursday (16Feb12), Sheen explained he was tired of playing nice.
He said, "I'm tired of lying... I'm tired of pretending the show doesn't suck... I'm tired of pretending Ashton doesn't suck.
"It's nothing personal... I just feel bad for him... He's saddled with such bad writing."
The outburst comes just days after Warner Bros. lawyers representing the show's producers insisted Sheen cease using an old Two and a Half Men photo to promote his new comedy Anger Management.