we always have that urge to fuck in the back of our minds and will keep a women as a "friend" only if we are fucking them or want to fuck them/be together..sad truth...
I completely disagree with this statement. I come from two fairly large social groups and I've always maintained a very close connection with many of the girls. I think it's important to be able to do this as part of being a healthy human being.
Now, admittedly these friends are absolutely gorgeous and I wouldn't even begin to deny a sexual attraction. But the idea that they are only, as you say, "friends" because I'd want want to have sex with them, or because I'm thinking about it, is well off the mark. They are friends because we share common interests, have years of beautiful shared experiences, understand each other and are always there for each other. These are my absolute closest friends I'm talking about, not just some temporary acquaintance who I'm aiming to use for a quick shag.
If anybody is unable to be in this position, then I'd wager that either you've just never met such friends yet, or if it is an
issue for you to exist in this kind of relationship, then you are somewhat sexually unbalanced, and would do well to reconnect with the other sex in a non-sexual context.
That said, in response to the OP, I'd say your husband is currently engaging in, or seriously thinking about, engaging in a sexual relationship with this woman.
My friends come as part of the package of being me. They are a part of who I am, and I could never envision a situation in which they needed to be hidden away, unless something was going on.