Just ask the girl! It's that simple. You'd be surprised how many MLs are shy to ask if you want more than just NHJ. Many are up for it for extra cash but whatever you do, don't be too generous with your money when you can get the same service at a shop for less than what some MLs may want to charge. The going rate is $100 for FS but some girls are willing to do it for less if not for the full session.