<human>: Recently my wife, brother, mom and I have been getting together a lot for dinners and such. My wife and brother sometimes will split off and just hang out without my mom and I. That part has always been fine with me, except as of late it's like they are the best of friends when we all get together. I realize, my brother's not going to be as excited to see the person he lives with (mom), but maybe hang out with me? We've always been pretty close (I thought). 

Anyway, so the other night they were out swimming in the pool for a couple of hours. We head on home, and my wife tells me that he revealed that he is bisexual. I've had a hunch for a while, but never knew for sure. He told her not to tell me, but as we are married we feel uncomfortable keeping secrets from each other. 

I do not care that he is bi, but I must admit I was ticked off that he told her before me: his own brother. It happened a week ago, and I was hoping that I would stop being offended fairly quickly. Instead, it seems the longer my brother waits to tell me, the more mad I'll be that my wife knew so much earlier than I did. The funny part is that I'm actually bisexual myself, but it never came up because I've been with my wife since high school. 

I know that I am being somewhat juvenile in my reactions, but how do I fix this? Obviously I can't make him trust me and come out to me. What do I do to make myself less upset? 

If you could offer some advice on how I can get over it, or if you've had something similar happen to you, that would be awesome.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Brother came out to my wife, hasn't told me, and I'm offended ~~at the lack of trust~~ that I wasn't told first.