No one is “entitled” to take ILLEGAL drugs/substances. And if it IS cocaíne that he’s using, it’s illegal. No one has a “right” to take illegal substances.
I’m a recovering cocaíne addict myself (I’ve been clean for 5 years, but once an addict, always an addict - one must be vigilant about one’s sobriety) I can assure you that cocaíne is EXPENSIVE. It’s not a cheap substance. If he’s using, he’s basically taking money away from providing for his children just so he can toot some Colombian marching powder.
The worst (and sadly hilarious) part is that cocaíne isn’t even a long-lasting substance in terms of how it makes you feel. Its effects may feel great, but they wear off in an hour or so. And then you have to snort more. And more. And more. And then you build up a tolerance (which happens FAST) and you have to use bigger and bigger doses as your addiction continues.
And yeah, from the “symptoms” and behaviors you’ve described… he’s almost certainly using cocaíne. I did many of the same things/acted the same way. And if his mates/pub buddies are using, your DO is using, guaranteed. That kind of “oh just TRY it, we all use it and we’re FINE” peer pressure is almost impossible to resist. He’ll have tried a bit once and felt great (because it DOES make you feel great.. at first.) But yeah, every single symptom and behavior you described, down to the later moodiness, is 100% cocaíne use. I would know, sadly.
And - he is not “entitled” to use recreational drugs. He has tiny humans who rely on him. He is responsible for their care and wellbeing. If he’s using, you need to either GTFO (as he won’t get clean unless he WANTS to) or tell him that he has to get clean, NOW, or you’ll report him and leave him and he absolutely will not get shared custody.
I got clean for my cat, because I’m responsible for her life, care, and wellbeing. If I can get clean for a cat’s sake, your DO can get clean for his children’s’ sake.
EDIT: (all of this is on the presumption that he is using/is an addict)
BTW I’m very honest and open about my struggles with addiction and my past drug use, so if you have any questions you want to ask, no matter how weird they may be, I’m willing to answer <3