my son used to do that a lot, he would do it at school too and were always called to school to get him dressed. he spent most of his time naked than clothed because it was a waste of time trying to keep him clothed. He will grow out of it. I tried to keep him in overalls, they find it hard to unbuckle and will not take them off. Now 12 years later at 14 yrs old he still takes his clothes off when he gets home from school down to his underwear and undershirt, I have to keep reminding him to wear pajamas or house shorts at home. They get used to it with repetition.

Thank you all. I keep him in footie pajamas at home but at school I can't... I found some onesie extenders on amazon that I may try. :)

Carters.com has several footie pajamas in stock online

Amazon.com has several 3t onesies if you want "shirt"s only. Some were labled 3t others looked like they were infants.

Footie pajamas. They were at walmart for black friday-christmas. I'm sure you can find them around. There was a store called just for kids in my local mall thy carried them year round.

My son has started taking his clothes completely off. He's 2 so it's a little easier to find. We rarely go out, so he pretty much lives in the footie pajamas! When he wears a onsie, he still manages to try to take his diaper out from it. Good luck! I know Wal-Mart has them that big. My daughter wears a 4t and we have been able to find them in her size there and most baby stores.