My son found my hustler, help!?

I am so embarrassed but I am not sure how to approach this. My son is 7 and for whatever reason came into my room, dug through my drawers and found a Hustler. My boyfriend bought it for me and I stashed it away, Now, I am upset b/c 1) what in the world do I say to a 7 year old? 2) how do i make sure he doesn't talk about it at school. 3) I don't want him in my room digging through my drawers and finding heaven knows what else! Sheesh! So, what should I say in the morning? .