Is it wrong that I’m (32F) disappointed my bf (42M) didn’t tell me he shared a hotel room with his female friend?

I’m in a ldr with my bf, who’s from Germany, and I’m from Malaysia. Recently, I found out that my boyfriend has been sharing a room with his female friend while traveling. The thing is, I already knew that this happened in the past when he was single, but what upset me is that he didn’t tell me in advance this time.

It kind of caught me off guard because I feel like he should have mentioned it, especially since we’re in a relationship now. When I asked him why he didn’t tell me, he explained that he didn’t mention it because she’s a bit complicated emotionally. Apparently, she has psychological issues and gets irritated when he talks about his personal life. In fact, she even told him she doesn’t care about his relationships at all.

I understand her reaction is probably more about her own issues, but I still feel like he should have given me a heads-up about it before the trip. I don’t expect to control who he travels with, but it’s about the communication. It makes me feel like I wasn’t a priority in that moment.

I know cultural differences can play a part here, since I’m from Asia, where boundaries between opposite-sex friends can be a bit more strict. I also know that it’s common in Europe for friends to share rooms when traveling, but I guess I’m just wondering if I’m overreacting or if it’s a reasonable thing to feel upset about.

I’m just looking for some perspective from others (especially those who are in LDRs) who might have experienced something similar.

Should I have expected him to be more open about this, or am I making a big deal out of nothing?

TL;DR - My bf (from Germany) recently shared a room with a female friend while traveling. I knew this happened before he met me, but I’m upset he didn’t tell me in advance. He says she has emotional issues and doesn’t care about his relationships. Am I overreacting, or is this something I should be upset about?