Do you gentlemen like it when a provider has snacks at her incall? What is your favorite sweet treat to have when going to see a provider (aside from the lady, of course)?

beer

And of course various beverages for replenishment and various chocolates..

Whipped cream works for me......

I like to have a drink and get go know the person. If there is something that the lady is thoughtful enough to have on hand it is an added bonus.

Plus having some fruit or other goodies on hand never hurts.  But that's a secondary consideration...we're there to see you, not for a meal (that's not to say we won't take you to dinner afterwards, if you so desire).