With massage parlours how can I tell which offer a happy ending
Here are some clues, one or more of which
may indicate you've found the kind of place that you're looking for:
All the girls wear short dresses or skirts and lots of makeup;
The place is a shit-hole;
All massage tables have a long sheet of what looks like kitchen roll stretched over them (to protect the bed and to mop up when you're done

);
There are notices on the walls of each room saying that no sexual services are offered (yes you read that correctly);
The room is barely bigger than the massage table;
There's nowhere to place or hang your clothes so you have to make do with putting them on top of your shoes, which are on the floor next to the bed;
The girls are visible from the street outside, waiting in the reception area and maybe even caught your eye as you walked past;
The shop is situated in a seedy part of town (e.g in London this means anywhere in Chinatown and most parts of Soho);
It's part of a large chain (Everwell, BE Health, etc, etc);
It's open late at night;
It has a neon sign outside showing "Massage";
It has a mobile number displayed on the signage as opposed to a land-line.
There's a queue of randy old buggers waiting in the reception area;
The girl asks you when you meet her, "have you been here before?";
She asks you to slip your pants off under the towel to avoid getting them oily (a legit therapist wouldn't do this).
It's generally the walkin places you're looking for. Anywhere which requires you to book in advance for treatment is more likely a totally legitimate therapy shop.
Don't ever risk asking for extras in a new place you haven't been to before. Wait for the massage to begin and she may "accidentally" bump her fingers into your balls or get a bit too close to your cock. Respond to it, e.g by opening your legs slightly or raising yourself up. Wait for to ask you to turn over.