DS 4 pooed in pants twice this week - never before?

[ghenghismaam]

Not sure if this is a good place to post this but it is behavioural...picked up DS (4) from nursery on Monday to be informed that he'd pooed pants. Now of course I know accidents happened, they are very easily distracted at this age, and they were playing out. What was slightly disturbing tho was the matter of fact 'I've squeezed out a poo' by DS so he obviously knew he was doing it. Fast forward to yesterday, in M&S - took him to wash his hands, then 5 mins later whilst browsing stuff saw him sit on the floor - 'mummy I've squeezed another pooh in my pants'. AArgh. He went commando for rest of trip .
He's not constipated, does healthy poos every day on loo at home, so I'm wondering if this is an attention thing, lazy boy thing or what?

It may be something or nothing. He may be being lazy or may be seeking attention. Has something happened recently to unnerve him? When DS was around 4, I starting dating my now DH (was a single mum up to this point) and DS responded by pooing behind the sofa, and once in new boyf's coat . So, just wondered if anythings gone on recently that may have spatked this?