I think it would only be insulting if you started DATY then after a couple licks pulled out the dental dam. Same thing goes the other way, if a provider advertises BBBJ and whips out a cover after you whip it out. Besides being safe which no one can argue with you about if you feel safer doing that, it might block the roughness of facial hair which has been a topic more than a couple times on the board.

if shes paying over $200 she can take the dental dam away from yo

Can only imagine they are all ok with a dental dam

o danger in it unless they are allergic to latex and it is latex... etc.  Always exceptions. I would only hope that not a single provider would be anything but pleased with being asked any question and go with any avenue that makes you more comfortable with being your own very sexy