Ball and Art Carney play Norma and Malcolm Michaels, a middle-aged married couple in midlife crisis: their anniversary is coming up, but he's decided he's tired of her and he wants a divorce. She feels similarly, and she agrees to a trial separation. Carney has really let himself go here. The former beanpole of his Ed Norton days is gone forever. In an early scene in the couple's bedroom, Carney's paunch is quite visible. This opening scene is unpleasant for other reasons too, with Ball's and Carney's characters insulting each other (very bitterly, not amusingly) and no real chemistry between them as performers.
Norma decides she's still young enough and attractive enough to make a new start ... so she heads for Las Vegas, where she meets quite a few handsome men. (Lucille Ball briefly ogles Arnold Schwarzenegger here!) Eventually she meets smooth-talking Peter Marshall, who sweet-talks her into his hotel suite. (Marshall is excellent here.) We can tell he's a playboy stud because he's got a waterbed. And he's ready to make Norma his next sexual conquest...
Ball actually does some good acting here, conveying her character's conflicting moods. We sense that she wants to jump into the sack with Marshall ... partly to spite her husband Malcolm, and partly to prove to herself that she still has some sexual appeal. Yet she also conveys that, on some level, she still loves her husband and doesn't want to cheat on him.
The reason why I give Lucille Ball only half-credit rather than full credit for trying something new here is because she clearly didn't trust herself to pull it off, and she decided to add some 'insurance' in the form of her usual so-called 'wacky' Lucy antics. Norma is wearing high heels when Marshall tries to get her into his waterbed. She can't get past him, so she jumps ONTO the waterbed and runs across it in her high heels. Of course, the waterbed springs several leaks. Marshall and Ball are running round in circles (or rectangles, rather) on top of the waterbed while it spews improbable gallons of water onto both of them, as if they're performing "Singin' in the Rain". It's only vaguely funny. I was hoping that Desi Arnaz would show up with his Cuban accent, shouting "It sprung a lick!". Instead, the ending we get is very obvious indeed.
I was also annoyed by the presence of untalented performer Sid Gould. In real life he was Ball's cousin-in-law, which is the only possible explanation for why she often gave this grossly unfunny man small but showy roles in her productions. I'll rate 'Happy Anniversary and Goodbye' just barely 4 out of 10. Nice try, Ball.