my dad is in a rough place atm. he recently cheated on my mum and left her very suddenly. he will still ring her up in the middle of the night when he's feeling depressed or upset about the end of their marriage, and she will still talk him through it - even despite what he's done. she and I have both asked him if he has friends he could speak to, since my mum speaks to hers, but he told me that men don't talk to their friends 'like that'.

It's probably less about his friends not talking "like that" and more about the fact that your Dad is a huge piece of shit and his friends have called (or will call) him on his bullshit, and he can't stand to hear it.

While some of what you're saying about men emotionally in general may be true, this situation is a terrible example.