You can get away with it in London. Source: experience.
You can cry on the tube and the bus, and the rule of “don’t make eye contact” means everyone just leaves you the heck alone and lets you get on with it it peace. I’ve twice cried while serving customers (after being bullied by a manager, two different jobs) and customers just try to get out of there. They might look at you a bit concerned but they mostly mind their own business.
I’ve lived in London half my life and I’d still ask you if you’re ok and offer you a bro hug. Now, if you’re a lass that’s a different dynamic and I’d probably just ask if you’re ok.
Not born a Londoner, but also don’t give a toss about being perceived as weird for being friendly.
That might be a bit awkward given I’m a woman!
It’s tricky, because I would feel worse if anyone asked if I was okay. I’m very much an introvert and would just reply with I’m fine, or just pretend to not have heard you. But other people might appreciate the offer of a tissue and a chat.
I have yet to muster up the courage to do that, i have recently cried at work, but managed to thankfully hide in a meeting room…