Teen sims changing their clothes itself...

[Aftershock]

Young sims changing their weekday outfits sometimes. Why? This started after I installed University DLC. So, DLC causes this, right? And can i disable this auto change outfit thing?

[Xautos]

each sim has 13 or 14 situational outfits, 9 you can change, a 10th can be changed in MCCC under modify career outfit. the others might be accessible with other modifications but typically they aren't easy to access and change. sometimes you'll notice some of your sims that you have sorted suddenly wearing crazy outfits you never seen, in those instances it's one of those situational outfits that aren't easy to get at.

There could be a few reasons for the automatic change going back on point though, it might simply be a flag that instructs the sim to dress in an appropriate outfit before doing whatever it is they are doing. For example you wouldn't expect a sim dressed in cold weather outfit to go outside in heat wave temperatures, they'll automatically change into hot weather outfit before going anywhere outside. Same with those sims going to exercise or going for a swim in the pool (unless otherwise overruled by a modification).

Some times it's just a flag to have a sim to dress appropriately before disappearing into a rabbit hole (When the sim is off the map but doing something like school, work, improving skills or something else), this also means dressing into work outfits as well (including scout outfits and big suits for the athletic career, plus a few others).

in some instances it wouldn't make sense to not auto change situational outfits. you wouldn't want your sim to die from overheating because you have them dressed in cold weather gear and they are outside in a heatwave, neither would you want your sims swimming in a swimming pool in their everyday outfit.