I’m not into it. Man or woman, I like to know who is in my house, and so does my hubs. There is too much personal stuff for people to get ahold of in someone”s domain; plus, it is eerie not knowing what exactly some rando is doing in your most private space–people are weird and do weird things from time to time, no matter how well you know them.
In your particular scenario, I would be squinting at my husband real s’picious like and let him know that his behavior was off, just so he’d be extra careful next time. At some point he should have checked in with you during a bathroom break, or just telling her he needed to let you know what the next part of his day looked like so you could plan around it. Secondly, he cleaned up, so he knew she was coming or suspected it at the very least? He really should have basic manners in letting even a roommate know there will be someone around should they want to hide anything away at the very least. Just because he trusts her does not mean anyone else has to. Lastly, he needs to be sensitive to the fact it is a woman that you don’t know, because you are his first priority and should be most worried about your feelings, just in case you weren’t cool with it. My hubs can’t stand when he is oblivious to something he does that ends in hurting my feelings because I’m his person and he always wants the best for me, especially since it upsets him as much as it does me when I’m upset (and vice versa).
I am lucky in the sense that my husband hangs out with men primarily, and women usually only by default when doing group activities or work stuff–just his natural inclination and I prefer it that way as I can’t help but want to protect my bond with my husband from any possible intruders in a way that I think of as almost an evolutionary defense mechanism. One of my brothers, though, has always had mainly very emotionally needy ladies as friends, and it has always made me roll my eyes (as I am very much not that sort of person to leech sympathy off of anyone). With my brother, I think he likes to feel like the hero or just likes to be needed, but it still makes me want to gag and I wouldn’t like it if my partner was that way because I don’t like the idea that any woman thinks she can keep him at her beck-and-call.
I am automatically supsicous of any woman who tries to hang-out solo with very attached men, knowing that the partner does not know them and that they mean no harm–I think man or woman can’t help but feel some sort of threatened, and it is the partner’s job to dispel this in a reasonable manner. I think it’s a respect thing with opposite sex friendships that the partner needs to be on good terms and comfortable with the friend, even if they don’t particularly like them as their own friends. In my mind, it’s more of a vibe thing–I feel most partners are watching the interactions of said friend to see if anything sexual/flirty is there and how much of an eye they need to keep on the relationship between the two. If it isn’t possible for the partner to meet a friend, say if they meet up out of town because partner is in their city on business, then it stays in a public place. To me it is all about courtesy to your partner above all else because you understand humans are not completely secure beings and you don’t want them to worry in any way that might damage your relationship.
If I were you, I’d be explaining all these points to my hubs and make sure he gets what I’m after before dropping it. If he acted any sort of odd or defensive, I would be digging to make sure he wasn’t up to any funny business. If he wants to explain his side and why he thinks you’re being unreasonable/controlling/etc., well then, you two need to figure out how you both feel about meeting in the middle, if it’s possible. It’s time for one of those talks that refines the relationship a touch more.