A girl started her period on the bus when a boy noticed. What he did has everyone applauding.

Every woman remembers a highly inconvenient time she got her period. Some of us have had it happen at the movies, or in the supermarket, or while we’re swimming. It’s awkward, stressful and even painful – and sometimes, we only know because it’s on our clothes.

So we can all imagine the stress that a leaked period would have caused one young school girl whose story has this week gone viral – were it not for the unlikely hero who helped her out.

In fact, what the hero did was so amazing, the girl’s mother posted a thank you to his mother for raising him right. Her post was then re-posted on the Reddit thread, ‘Little humans being bros’.

In the post, the woman explains that her daughter started her period on the school bus, and a boy in the year above her pulled her aside to tell her “she had a stain on the back of her pants.”

And then, most helpfully, he loaned her his jumper to tie around her waist so she could get home without feeling self-conscious.

What a gentleman.

A screenshot of the post. Source: Reddit

Explaining that her daughter had indeed been embarrassed, the mother added she had initially refused the offer - but the boy insisted, for a very sweet reason.

"I have sisters, it's all good!" he told her.

The girl's mum was so grateful that someone had helped her daughter in this way, she wanted the boy's mother to know, "If you are this boy's mum, I want to say thank you and that you are raising him right!"

Naturally, the post was met with applause from Redditors, who agreed that the boy was indeed a stellar human being.

"Very chivalrous of the boy. Good on him!", one commented.

"How impressive that he thought to do this even. When I was in middle school if I saw this I’d probably never put two and two together or thought to help this girl out," said another.

The comments section was also filled with sisters sharing stories of times their brothers helped them, and brothers who said they'd do anything for their sisters.

"My sister and I were close in age, and fought like cats and dogs at home. But outside the house, we had each other’s backs, and I guarantee I would have messed you up if you had hurt her in any way," wrote one loving brother.

One commenter noted that perhaps it was the boy's dad who should be credited for his kindness. Nevertheless, the incident proves that not all heroes wear capes - some of them simply let us borrow their jumper.

Faith in humanity restored.