Shania Twain says she's not holding a grudge against her ex, Robert "Mutt" Lange ... despite him cheating on her with her close pal, Marie-Anne Thiébaud.
In fact, speaking on the "Great Company with Jamie Laing" podcast ... the singer said she felt quite sad for Robert ... 'cause his affair ended their 15-year marriage in 2008, so it's all his mistake and his baggage to carry for life -- not hers.
Shania said, "I'm sad for him that he made such a great mistake that he has to live with. And I don't know what that is, but it's not ... That's not my weight."
She also shared her zen approach to forgiveness ... saying when it comes to people like Mutt, she believes in letting go and understanding why they messed up.
Also, Shania's ability to move on might have come with a side of revenge. After Mutt and Marie-Anne's affair, Shania leaned on Marie-Anne's then-husband, Frédéric Thiébaud, for support ... and, of course, we all know what happened next.
Frédéric and Shania tied the knot in 2011 and are still going strong!
Shania's previously credited her new husband for keeping a much cooler head about their exes' affair than she did -- but sounds like she's found some peace now as well.