The Good Life star, 67, and director Michael Rudman, 75 - Kendal's second husband - were together for seven years after tying-the-knot in 1983. Years after their marriage broke down, the pair, who have a son together, reunited in 1998.
The star told Good Housekeeping magazine: "Michael and I talk about marriage and then we decide we can't be a****.
"I think marrying the same person twice looks like carelessness - that's the way we look at it!" Asked what she had learnt about love, the actress replied: "It comes and goes" and she said of what draws and keeps individuals together: "Sex! (and) more sex!"
Kendal, who famously played Barbara in 1970s sitcom The Good Life, has previously told how she gave up Botox because it looks "silly" on women of a pensionable age.
"There is pressure in the movie business (to look a certain way), but I'm not in that."
Kendal said that thanks to yoga, Pilates and weights, she is "fitter and stronger now than 20 years ago, and I've never felt so good."