Almost two decades after their contentious divorce, comedienne Roseanne and actor Tom Arnold got back together for one magical night. Well, sort of. Although the 53-year-old actor was adamant that he would have no part of his ex-wife's roast on Comedy Central, he apparently had a change of heartless at the last minute. Arnold opted to be a part of the festivities. A show insider told TMZ that the Madea's Witness Protection star first refused to take part in the roast of the controversial comic, who he was married to for four years. But it appears that Arnold waffled on his decision at the very end. Arnold reportedly reached out Comedy Central, agreeing to join in on the fun. And for the first time in YEARS, the exes agreed on something -- Roseanne signed off on having him there. Among Arnold's jabs at his former wife, "She may not be the perfect wife, but she is literally the worst f-ing EX-WIFE on the planet ... trust me." One source tells TMZ that behind the scenes Arnold and Roseanne actually had a "moment" together for the first time in 17 years. Perhaps they've mended fences for good.