tee-shirt dresses okay?

I’ve gotten away with this a couple of times but want to know if its illegal or not allowed in schools. i’m a girl and at first kinda on a dare but more to turn on my gf i wore nothing but a tee-shirt, shoes and socks to class. now im talking about xxl or xxxl mens tees here, they go almost past my knees. im pretty flat chested so i dont ever wear a bra on a normal day and ive skipped panties a couple of times with modest skirts *blushes* so i guess my question is would it be okay to make this a regular thing? would i get in trouble? i’d probably wear panties under them going forward but i just really like how it feels. i dont feel slutty, the shirts kinda smother me in their size i actually feel a lot more covered then i would in say, skinny jeans esp. designer ones. but i’ll admit it turns me on a little *blush* especially walking across campus outside. is this slutty? or against any rules? would anyone else/has anyone else tried it? im basically wearing the tee-shirts as really comfy cotton dresses. and none of them are white, most are dark colored.I’m not American so I doubt I can answer your question with the correct amount of knowledge needed, but… I would say if these shirts almost go to your KNEES, they’re fine. As far as I know there are people in America that wear clothes much much shorter, so what if it’s a t-shirt, it’s covering you up wrought for you to be modest. and underwear is a choice. It’s bot like there is a law that makes women/girls wear underwear if they are wearing clothes outside of it.