You know what, I’m not convinced by the accidental text theory.
I used to make that mistake fairly regularly 20 years ago when I had a basic phone and had to write the message first, and choosing the recipient was the last thing I did before sending. But now with smart phones, you have to choose the person first, there is often a photo icon of them, your conversation history pops up before you even start writing. I have NEVER sent an accidental text since having a smart phone.
He might have sent the message as a genuine if clumsy attempt to ‘keep you informed’, or as a lazy opener to a casual chat. Perhaps he expected questions about whether it was a nice room, but when he got a suspicious response it turned sour.
Could he have gone to the hotel early to get some work done prior to the trip?
If it is a nice hotel funded by his work - could he perhaps just have wanted to take advantage of a nice lunch and dinner paid for on expenses?
Could he perhaps have wanted time to use the gym equipment, or watch the planes from the bar and enjoy the experience? Sounds silly perhaps, but it’s what I’d do, I love airports!
I wouldn’t automatically jump to the worst conclusion @lopdedop . It looks bad, but when you really think about it the mechanics of it, the other woman accidental text don’t seem at all likely.