Several dozen episodes of Cheers ago, Jackie Swanson and Woody Harrelson were rehearsing a courtship scene between bartender Woody Boyd and his sweet, naive, insanely rich girlfriend, Kelly. ''Woody was making a joke about a wedding tradition where the groom shares the bride with all his friends,'' says Swanson, ''and suddenly he said, 'You know, we'll be married eventually.' I said, 'Sure I'll believe it when I see it.'''
Believe it. On May 14, in Cheers' hourlong season finale, Swanson originally cast for just one segment three years ago will walk down the aisle, vowing to love and honor Harrelson till cancellation do them part. It's quite a step up for the unmarried, 28-year-old Michigan native, whose parents were ''heartbroken'' when she left Northern Michigan University to try acting eight years ago; Swanson herself wasn't exactly encouraged when she took home her first acting paycheck for a role in a Prince video (''I was the 'Raspberry Beret' girl, and I made, like, $35''). Now her Cheers future seems secure, if mysterious. ''Will Woody and Kelly have a baby?'' she muses. ''I have no idea. I never thought they'd even get this far.''