You may not get anything more than a massage (But usually a good one at that.).

To maximize your chances, smile and try to make a little banter with the gal, especially after you flip over.   See if she makes eye contact with you.  If she does, that is a very good sign.  Smile a lot and tell her how pretty she looks.

If things look good so far, say something like:  "I wonder if there's other things we could do?"  If she ignores this, then it probably isn't going to happen, but if she takes the bait, you'll probably home.

She might say something like:  "What do you like?"  Don't get greedy or too obvious yet.  Say:  "Do you do extras for a good tip?"  If she nods, then say:  "I've got X amount of cash (Be sure to bring your wallet with you.), can you undress and we'll hug and kiss?"

She'll know exactly what you mean.

In my experience, 2/3's of the time you will get at least a happy ending, and 1/3 of the time you will get full service.  The service is often excellent too.

Also, some gals will only start with a HJ, but if you see them again, they will escalate to greater things.

I am a big fan of MPs, I used them for half the hobbying I used to do before the age of the internet and TER.  I've met some wonderful gals there, many whom I still see outside of the MP for many, many years.

You should know that authorites are going after MPs, especially AMPs like never before, so do be careful and keep an ear to the ground for local LE activity.