Two therapists in the middle of the afternoon
A booking with two therapists is markedly easier to arrange for two in the afternoon than for ten at night, and the reason is entirely about diaries. It changes three things in the room as well.
Two therapists at once is the booking that most often runs into a scheduling wall, and the wall is always the same one: two people have to be free at the same hour, and in the evening they very often are not. Move the request into the afternoon and the arithmetic changes considerably, because afternoons are the part of the diary with room left in it.
That is the whole practical case, and it is worth knowing before you decide that the booking is impossible on the dates you have.
The figures
Two therapists with one guest runs at EUR 360 an hour, so EUR 540 for ninety minutes and EUR 720 for two hours. A couple with two therapists is EUR 720 an hour. A block of eight hours with two therapists is EUR 2,880 for one guest and EUR 5,760 for a couple. Every combination is written out in full on the profiles, which is where to check rather than working it out from an hourly figure.
Half travels first on any booking with two therapists, at any length and at any hour, including a same-day one from a guest the house already knows. That rule has nothing to do with the clock and everything to do with the fact that two diaries are being held rather than one.
Three things it changes in the room
The first is space. A standard central Amsterdam hotel room, particularly in an older converted building, is not large, and two people plus two bags plus you is a different proposition from one. It is entirely workable and it is worth thinking about where things go before anybody arrives.
The second is the arrival. Two people crossing a lobby together is marginally more noticeable than one, which is another quiet argument for the middle of the afternoon rather than half past two in the morning, when a lobby has one member of staff and nothing else to look at. They arrive as guests, in street clothes with small bags, and go to the lift.
The third is the opening few minutes. Each of them decides what her own session includes and each says so in her own words, which takes slightly longer than one person doing it and is worth the time. Two people, two sets of limits, both named at the start and both holding for the visit.
How to ask
Name both women if you have read the profiles and chosen, and give the hour second rather than first, because the hour is the flexible part and the pair is not. If one of the two is not free at the time you asked for, the reply says so and says who is free; nothing is decided for you and nobody is substituted. In practice the usual resolution is that the hour moves rather than the name, which is precisely why the afternoon is the easier request.
Write earlier than you would for a single booking. A pair for a Saturday afternoon is a reasonable ask on the Wednesday and an unlikely one on the Saturday morning. Length is worth thinking about too: ninety minutes is the shortest rung that makes sense with two people in the room, because sixty minutes has three minutes of practicality at the front of it and then very little left.
Couples, and the same booking with four people in it
A couple with two therapists is the largest arrangement bookable here at EUR 720 an hour, and everything above applies to it twice over. The room question becomes real rather than theoretical: four people and two bags in a standard central hotel room is a lot, and a building with larger rooms, or an apartment, makes a noticeable difference.
Both guests have to be twenty-one or over and both may be asked for a photo document at the door, looked at once and handed straight back. Anyone else in the room, including somebody who is only there to watch, has to have been mentioned in the thread while the booking was being arranged rather than appearing on the day. The age statement sets that out in full, and the afternoon is again the easier hour to arrange it in, for the same reason as everything else here: four diaries are harder than two, and afternoons have room left in them.