A guy I know (not, most definitely not, a friend) has just been dumped by his third wife. He cheated on the first two, the second with the woman who became the third wife. Now she's left him for another woman.
Cue comments about "poor old Phil, it'd be less of a blow to his ego if she'd left him for another bloke," and "well that tells him he's inadequate." And a lot of sniggering.
It's not though is it? She was probably bi. What's this warped thinking, toxic masculinity? I think it's crazy thinking. She'd just had enough of him probably. There's also a 16/17 year age gap.
It's probably an extension of the old attempt at an insult when a woman isn't interested in a man she must be lesbian.