Oh, my pleasure and that's not a stupid question at all! Yes, you will be naked from the waist down but your esthetician should provide a towel to drape over your tummy, or if she doesn't, you can certainly ask for one. Yes, she will see everything but remember this is her occupation and is all in a day's work. Also, she has the same 'parts' so she's seen it all before--no surprises there

This might sound odd or funny but because of our various nooks and crannies my esthetician will sometimes ask for me to hold a particularly difficult to get to area taught while she waxes. I find being part of the process helps alleviate any embarrassment I might have.
As a good friend of mine suggested to me before my first Brazilian, "be prepared to leave your dignity at the door".

Indeed!