You are not being oversensitive. A conjugal relationship is not defined just by bumping private parts in the dark. Marital intimacy is about more than that. It's also about the personal confidences that are shared throughout daily living. As you saw in those text messages, he is doing that with this so-called friend.

I am amazed at how often I am seeing threads here where a person in a committted relationship is distressed by a partner who wants complete freedom of interaction with single (or even married) persons of the opposite gender. Nonsense. This idea that a married person has a right to the same kind of "friendships" that a single person might cultivate is a crock, IMHO.

So she put the kids to bed and now she's tired. No! I'm sorry . . . that is not normal, friendly sharing between a married man and a female friend. That is intimacy. And I don't, for one minute, believe he'ld be just fine with you having similar message exchanges with some man you were "friends" with.

A female co-worker texting him to share some workplace scuttlebutt or hot gossip might be more normal, but not the text you described. She is subtly flirting, and he is eating it up. When two people marry, they become a social unit - a package deal. Each may have friends of the same gender, but one does not have friends of the opposite gender. You and he, as a couple, might have a male or female friend who is single, but the two of you would relate to that person more-or-less as a couple. That person might be invited to your home for dinner with both of you and might take the two of you out for dinner now and then. The three if you might socialize together. But private, little sharings, via text, about how one's day is going? No . . . no . . . I don't think so.