Sports bra under muscle tee

I'm a 16 year old athlete female who goes to dance practice everyday. I was running out of t-shirts and the weather gets hotter by the hour. So I decided to wear one of my muscle tees I have. I wore it with a sports bra because I felt a regular bra would've not been ok and since I was working out, a sports bra would've been fine. After practice my mom picks up and all of a sudden, we get into arguement about the top part of the outfit. Like always, she thinks my opinion is wrong and if I didn't have a undershirt, then I should just wear a t-shirt. The last thing I said was, "U would let just wear a sports bra the pool, so what's the difference?" The pool and the park are both public places where there's going to be ppl, families, and creeps walking around. She got mad at me about that. Then the next last thing I said was, "I guess we are going have to buy more laundry detergent if you want me to wear certain shirts." Even though I knew I was wrong with my attitude part but is it ok to wear just a sports bra under a muscle tee?