Just because guys don't sit around and share their deepest feelings, it doesn't mean that male friendships are inferior to female friendships:
"If we use a women's paradigm for friendship, we're making a mistake," says Geoffrey Greif, a professor at the University of Maryland's School of Social Work, who has studied how 386 men made, kept and nurtured friendships. Men might not be physically or emotionally expressive, he says, but we derive great support from our friendships.
Researchers say women's friendships are face to face: They talk, cry together, share secrets. Men's friendships are side by side: We play golf. We go to football games. [...]
A woman from Wisconsin wrote to me recently to say that she effortlessly shares intimate feelings with her friends. That's in great contrast to her husband. He recently went on a fishing trip to Canada with four longtime friends. And so she wondered: What did they talk about for a whole week? She knew one of the men had problems at work. Another's daughter was getting married. The third man has health problems. Her husband said none of those issues came up. She couldn't believe it.
She told him: "Two female strangers in a public restroom would share more personal information in five minutes than you guys talked about in a week!"
Sounds about right! Link
...and that's why many men don't trust women. Not only do some women habitually do this, they do it with their partner's confidences. Eventually, the partner stops confiding in those women. Shocking, eh?
Men are often very private. Intimacy opens that up; it's quite a shock when that turns into public information, though. Tends to modify behavior a bit.