I recently experienced something similar. My cat was angry as hell I tried to give his little brother a bath. And this cat loves me and kinda hates him. I guess it was the principle of the matter.
I was bathing my younger cat Gadget because he's itchy and scratching himself up, and he's yowling cause he hates it...
And Gizmo, my loving boy, leaps on my back to scratch the shit out of me in defense of his younger 'brother'
Gizmo is madder about the whole thing than Gadget
Everyone feels better on amphetamines.
They won't work forever and you don't get to amp up your brain every day without paying for it.
To say nothing of addiction. It's hard to want to give up that amazing feeling.
I'm not against it, but you should go into drug use eyes open.
Nothing the ex says is going to be any good for his current relationship.
It's probably something like "you were the one, I messed up, I missed you so much," and "all I want is one last time together."
I don't know if he should or not but he'd be walking into a minefield.
Not long ago in a comment I suggested women show their husbands acts of kindness/affection so they're not vulnerable from being starved for attention and affection, and the women absolutely lost their minds at the suggestion.