If she asks how do I explain to my mom..

Two days ago I decided to buy two thongs and their matching bras bc I wanted to try out thongs for the first time. One of the bras is essentially “sexy” and the other one is pretty normal. If she finds them and asks, what do I say? I didn’t but then to hookup, I don’t even have a bf. I just like buying matching sets. I’m 16 and I’m scared she’s gunna use my age against me.