What is with my kids and tampons??

So last week, Erin told me she needed to go potty. Mind you, we're not really working on potty training -- she goes at school during potty time, and I'll put her on if she asks, but I'm not doing the "do you need to go potty?" every 5 min. When she does go #2, however, she does get 2 M&M's, which are her favorite thing on earth.

So she goes potty, and I say, "Good job, Erin! Now you get 2 M&M's!"

She says, excitedly, "I get a prize!"

We have never once talked prizes. I look at her and say, "No. You don't get a prize. You get 2 M&M's."

She hops off the potty, pants around her ankles, and runs down the hall to my room. She goes into my bathroom, opens the cabinet, pulls out a tampon and says, "I got my prize!" She then proceeds to spread her legs and place the tampon down there, looks at me and says, "I stick it in my bottom?"

"No, no!" I say. "That's not a prize. You don't stick it in your bottom."

She says to me, confidently, "When I'm a grown-up."

Note to self. Erin is too old to be in the bathroom with me.