As others have noted above, it's your dime so within their boundaries, I've found all the good providers I've seen more than happy to have the session go the way you'd like!  Of course, if you're planning on seeing the girl again, putting a smile on her face may make her a little more responsive to your calls!  And as far as the legitimacy of their enjoyment, as anyone who's seen "When Harry Met Sally" knows, only she will ever REALLY know for sure!  That said, if some of the lovelies I've been with were acting, they were amazing at it!