I value and respect the words of the mono people here, CTF and the various husbands mentioned. Men are certainly discouraged from sharing their deepest emotions with others. It's ingrained in our society and has been for millennia. I find that so sad, and unhelpful for our modern society. It's becoming outmoded and causes devolution, in my opinion. I encourage men to take the leap, to trust, to get outside perspectives on their emotional issues. I think a board like this is great for guys, even if they only read and never post.
Poly men are generally outgoing and curious guys, I have found. Like me, they enjoy sampling the banquet of our fellow human travelers while we are here existing on planet earth. So much to learn, from so many interesting people! It's like traveling to a foreign country and sampling the language, the culture, the landscape, the food, the folk art, without the hassle and expense of traveling.

It's broadening.
My current boyfriend prefers the company of women over men (although he does have a couple guy friends), and even though I don't think he's ever actually had concurrent emotional romantic relationships, he is very friendly and loves to engage with the ladies. I guess he's kind of in touch with his feminine side. He just seems to love to have a variety of friends to bounce ideas off of, listen to music with, go places with, etc. He even likes clothes and thrift store shopping.
My ex husband was more like the "typical guy" being talked about here. We were together over 30 years. He had a few male friends, but no one he felt safe really letting into his heart. He suppressed, hid and lied about his attraction to other women, to "set a good example" for me.
He had low self esteem and that colored all his interactions, and also his attitude toward my friends. He always knew I was poly, no matter how I suppressed it and tried to downplay it. However, he was even suspicious of my conversations with female friends I went to for support. He expressed a real fear all we did when we talked was "bitch about our husbands." Which was very insulting really, as if we had nothing else to talk about! Like our kids, our jobs, our hobbies, travel, our cultural and sports activities, etc. Heck, even girly things like nail polish, home decorating, what kind of bra to buy. lol
I think it can help any marriage/coupleship to have other good friends at the very least. Like Girl/Tex said, it's exhausting and challenging to be the sole emotional support for someone. It's not particularly healthy. It's a shame some people feel the need to keep everyone else on the planet, besides their spouse, at arm's length. I suspect, like with my ex, it stems from childhood trauma. A shame to live that way one's entire adult life.
Life is short. I am getting older. I am 60. I still want to keep getting out there with people and make new friends, old and young. I do love to chat with younger people as well as my peers. It's so refreshing to hear what they find important in this quickly changing world of ours. It's like a view into the future. I am also even open to dating men much younger than me just because I enjoy their energy and humor. (Well, and their libidos, I must admit.) lol
I am not here to force anyone to see things my way. Everyone is on their own journey. But please, monos, try to not feel threatened too much when your wife meets someone new and feels a new energy and excitement about life. That's just normal. My gf and I are very close, but sometimes if we don't socialise enough, separately or together, we kind of run out of things to talk about. Getting together with other people brings out new aspects of ourselves and makes us more interesting to each other, and actually does strengthen our relationship, challenges us and forces us to keep growing, not stagnating.