Imagine an unmarried couple in their mid-twenties, both educated (teachers). They live in Vienna of the early 1930es (before the Anschluss).
That's kind of very hard to imagine, as this was completely contrary to what society found acceptable at the time. You're looking at the past with the mindset of today. That won't work, and it's a very common made mistake.
An example of that are gladiatorial games. I've heard lots of people say that they found them to be horrible, incomprehensible, repugnant, etc. That's looking at the games as we see them now, with our morality. Back then our morality hadn't been invented yet. So if you are a real sport-fan today, you would be in Roman times. Consequently, you would love the gladiatorial games.
Those two teachers, are they of the same sex? If yes, they could share an apartment together to save costs. They would have to have separate bedrooms, or at least two single person beds. Family, friends or the landlord would not accept anything else. They could put them together in the evening, or have a guest room with a twin bed in it, 'for guests'. But they would have, in that case, two separate rooms with a (single) bed in it for the partners.
Some gay couples lived their lives that way, where society turned a blind eye, mostly because people simply couldn't imagine gay people living together. It didn't enter the mind. Two men or women living together to save money was quite common, and completely accepted. Another ruse used was one of the partners being the secretary of the other, or lady in waiting.
Teachers didn't earn a lot of money, unless one of them was professor. So living together to save money is your most likely option.
Are they a man and women? Then they would in all likelihood not live together. Almost all landlords strictly forbade it. Their respective families would put great pressure on them to get married real soon.
Common behavior at that time would demand chaperons being around, and one of them would have to leave in the evening. Sleeping overnight was usually not allowed in boarded lodgings. A teaching couple living together would not be acceptable to the school management.
I can give you an example from the early 1990's when I was teacher: I was asked what my religion was. I don't have any, and was raised Roman Catholic. Sorry, the Dutch reformed school said to me. All our teachers must be Dutch reformed, and practicing it. We don't want a Catholic teacher, and certainly not an atheist. The fact that I wasn't married was also questioned. You are not married? Are you engaged? Why aren't you? I told them my last relationship had just ended. Which was technically correct. I didn't tell them I was gay, of course.
(I don't think I have to write I didn't get the job. Nor did I want one, giving their interrogation. Yes, this was even back then exceptional in The Netherlands.)
That was in the 1990's. Now imagine that during the 1930's, with MUCH stricter morality.
After my lengthy answer I see that you want them to stay in a hotel room. Oopsie. Not completely an oopsie, because the above applies as well.
In that case, they would book two single rooms. Or a larger room with two - single - beds in it. Very likely the management would see in their passports or ID cards they aren't married. Many hotels would not accept an unmarried couple booking a single room with a twin bed. As teachers they cannot afford a large room or suite with two twins in it.
Most hotels would book them automatically in different rooms. Many of them would (intentionally) place them far apart or on different floors. A quiet and generous tip might come in handy, to change that.
Living in a hotel room infers - to me at least - a more permanent stay. Not a holiday or a weekend trip. Living in a hotel was only affordable for the very rich. Certainly not for teachers.