Then book with a provider who offers just cockworship sessions if all your looking for is a blowjob. That way she knows your just seeing her for that.
I will say your comments "I'll tell you when I'm done getting my dick sucked not you" and "its our job just to suck dick" wont sit well with many ladies here. Trying to force someone to keep doing something when they have had enough is not cool and anyone who makes them is fucked up.