Cat,
It sounds as if yer going into your friendship with yer YF with the right motives. Above all it shouldn't be sex driven.
Yes, you might be curious, but then after all what is love all about............"Accept me for who I am naked in your sight". In other words REAL friendship is about feeling calm & content with psychological nakedness. I know with my Younger Friend I have no need to hide anything from him.

Look into your soul, heart, & mind & if it's clean towards your YF then maybe it's the learning experience you need. I know for me it DEFINATELY IS. I am SURE that God intended it.

Hope this makes sense & applies,

Kristian