Aitah for asking my boyfriend why he sleeps with his sisters

My (31f) new bf (27m) I've been with just one week has casually mentioned that when his older sisters come to visit they usually sleep in his bed, with him.

He is the youngest of all his siblings and he comes from very tight closed knit family. This seemed a little weird to me but it got even weirder to the 9th degree when on a trip to the woods where they rented a cabin, him and all his siblings including his two older sisters, and the sisters all slept in the same bed with him.

There wasn't enough rooms for all of them and let alone enough beds

This wasn't limited to just night time, when they also take naps they will also share the same bed.

I finally asked him if he sleeps with his sister's constantly in the same bed. I could tell the question made him a little uncomfortable but to be honest I'm very uncomfortable.

This all started if I have to be honest from when he showed me a text message between them. In the text message she addresses her brother followed by this emoji 🥰. He responds to her text message with "Thanks love".

Keep in mind he's not British he is American, and he does not normally use that kind of vocabulary to address someone. So to me calling your sister love is a little odd... and then this whole sleeping with your sister in bed it's just Amplified everything