Dog obsessed with sniffing toddlers bum

[shouldistop]

We have 2 kids and he doesn't do it to the 5yo (even when he was 3), toddler is 14 months and ddog loves to sniff his bum and tries to lick it when he's naked!
Does anyone know why this is? He also sniffs his face but doesn't lick it.

Your toddler has a lovely smelly bum for your dog

I wouldn't worry (although also wouldn't encourage it). Dogs like poo smells, as my mum used to say to my sister and I if our dogs chose to sit by one of us .

That’s where the chocolate malteasers dispense

He's absolutely obsessed 🙈 even when he's been in a bath so completely clean although I suppose his sense of smell is very good.
He doesn't sniff 5yo's bum even though it's probably less clean sometimes