AITAH for keeping clothes i bought for my nephew at my house

for context ive always bought my sister clothes and shoes for my nephew to keep at their house. he's 2, i've been buying him so many cute clothes since he was born. i recently just bought him a few outfits and a pair of new balances to keep here at my moms house. me and my sister have similar a fashion sense and i love styling my nephews little outfits! i frequently get him and take him out to places. there's some days i want to pick his outfit out for the day and i'll have to text my sister can she pick “_______” out for him to wear. sometimes she can't find certain outfits or some thing is dirty.

before a few weeks ago i had 0 clothes for him at the house. i decided it would be easier for me to pick up a few clothes and a pair of shoes for him to have here. one of the days i picked my nephew up from daycare we were heading to park. i wanted him to wear one of the sets and shoes i just got him. i sent my sister pics of him and she loved his outfit. when i dropped him off i changed him back into what he had on earlier. i kept the set and shoes i bought at the house. i felt kind of wrong doing that, and it wasn’t to be malicious. i would like to start keeping some clothes for him to have at our house.

the other day i was gonna take him to a splash pad but we ended up not going. i told my sister i bought a pack of boxers so he can have can have a dry pair when he gets out. we did go to another park and he had on some of the play clothes i have for him to keep at the house. when we got home my mom was changing him back into the clothes he came in. he still had the boxers i bought on and i asked her if she could switch him into the ones he wore here. even though i already told my sister i just bought those and she didn’t seem to have a problem with it i still felt a bit weird. however only 3 came in the pack lol and i know he has plenty at their house.

ive seen a lot of parents online thinking a family member having separate clothes for their child at their house is “possessive” and “creepy”. a but i genuinely don’t mean any harm by it, he has plenty of clothing at their house. i still do feel weird about it though. i talked to my mom and she said my sister should understand about me wanting to keep some stuff here and that it’s good to have.

im really asking from a parents perspective AITAH.