Can one of you watch during a couples massage, rather than lie down and receive one. It is asked quietly, usually in a follow up message after the main booking questions are out of the way, and it comes from two completely different places. Sometimes it is a sitting out question: one of you does not want to be touched tonight and would rather be in the room than out of it. Sometimes it is the other thing entirely, and the person asking already knows it. Both are ordinary requests, and they are arranged differently, so it is worth separating them before anything is booked.
Sitting out: one receiving, one present
This is the common version and the easiest to arrange. One of you is worked on for the hour; the other stays in the room, in a chair, with a book or a drink or nothing at all. Booked that way, and said plainly in the message, it is priced as a single guest with one therapist, on the single-guest row, because nobody is working on the second person.
It suits a specific set of evenings. Somebody who is not in the mood but does not want the night to be cancelled. Somebody who would rather see what this actually is before booking themselves into it next time, which is a genuinely sensible way to arrive at a first session. A person travelling with someone who has been wanting this for weeks, who is happy to be the audience and not the subject.
What makes it work is deciding on it in advance rather than mid evening. A therapist who arrives expecting to work on two people and finds one of them has withdrawn to a chair reads it as a problem she has caused, and spends the first ten minutes managing that instead of working. Say it in the message and the whole thing is frictionless.
What makes it not work: sitting in the chair with a phone. The person on the table can feel the difference between being accompanied and being attended to by somebody scrolling. Put it face down.
When watching is the point
The second version is a request rather than a logistics question, and it deserves a straight answer. Some couples want one of them present and watching while the other receives the massage. It is not an unusual thing to ask, and whether it suits her is each therapist's own decision.
Say it in the message, in plain words, before the booking is confirmed, rather than raising it once two people are in your room. Each therapist sets her own limits, tells you what they are before the session starts, and they hold for the whole visit; she also decides for herself whether to take the booking at all. A request produced halfway through an hour means asking somebody to reconsider her own limits on the spot, in a room where she is outnumbered, which is not a fair position to put anyone in.
The boundaries guide covers how to put this kind of thing in writing without a long preamble. The short form is: say the thing, in one sentence, with no euphemism. Everyone finds that easier.
The question underneath the question
Very often the couple asking whether one of them can watch are really asking whether the two sessions in the room have to be identical. They do not. That realisation solves the problem without anybody sitting in a chair.
Two therapists working simultaneously can be running two quite different hours. Firm, thorough, classical work on one side of the room and something considerably slower on the other is the normal state of affairs rather than a special arrangement. If one of you is hesitant about a particular format, the fix is usually to pick a different one for that person rather than to opt out of being touched altogether. Whether the two of you have to want the same thing goes through that in detail.
Watching without meaning to
There is a third thing worth mentioning because it surprises people. In a side by side booking, both of you are receiving, and yet the question of looking still comes up. The tables are close. At some point one of you turns over and the other is right there.
Almost nobody watches, and the reason is not modesty. It is that the first ten or fifteen minutes take you somewhere else entirely, and by the time you would have thought to look, you are not thinking in those terms at all. Couples who worry about this beforehand consistently report afterwards that they forgot the other person was there, which sounds unromantic and is actually the highest compliment the format receives. What two therapists in one room really means describes that drift in more detail.
If you would rather it not be possible at all, ask for the surfaces to be angled away from each other, or set with more distance between them. Thirty seconds of arranging, no explanation needed.
Booking either version
For the sitting out version: one therapist, the length you want, and a line saying only one of us is having the massage. For the other version: say that one of you would like to watch, clearly, in the first message.
Both get a reply with a name or two names, and an arrival window of forty to sixty minutes once confirmed if it is for tonight in the centre. Half goes ahead for a first booking or anything arranged a day out, either way, and the couples booking page describes the usual side-by-side format.