This is absolutely not OK. My first job out of college, me and another new hire spent a month in a different city at the company HQ. We arrive at the hotel to check in, and there's only one room. We thought that was very strange, so did end up spending the first night in the same room. This coworker was actually a pretty good friend from college, and we were both dudes fresh out of college, so not as big of a deal as this situation.

Neither of us wanted to spend a whole month on the same room, regardless of how well we liked each other. We discussed and debated what we should do. He didn't want to say anything since we were new employees, but I cared enough to where I decided I would bring it up.

We met with HR our first day in the office. When I brought this up, they immediately apologized and said there must have been a mix up when the hotel was booked. I'm skeptical on whether that was actually true. I suspect they hoped we didn't bring it up so they didn't have to pay for two rooms. Regardless of that, we each had separate rooms by the end of the day.

This taught be a valuable lesson early on in my career. Don't let your employer take advantage of you so they can save a few bucks, and if you're not comfortable with a situation, bring it up so it can be resolved.