This happened a few years back, but someone brought it up recently and I thought I'd share. It might have been a dick move on my part, but hopefully the guy learnt a lesson.
I'm a woman, and about 10 years ago I had super long hair (past my waist) that I decided to donate to charity (The Little Princess Trust in the UK in case anyone wants to do anything similar). I also decided to fully shave my head to raise some more money, and was completely bald.
About 6 months later my hair had started to grow back, and I'd styled it into a cute short pixie cut. I was out in a pub with some friends, and a random guy was trying to flirt with my friends but was being a complete dick to me. He was just being genuinely nasty, talking about how I was "disgusting" and "unnatural", and telling my friends they should ditch me.
I'd had enough of him after a while and asked what his problem was. He told me he couldn't stand "dyke bitches", that I was going to hell like all the gays, and was probably going to force myself on the other girls when they were drunk because "that's what you're all like". Not that it matters, but I'm straight and had never talked about my sexuality with this random guy, or had been flirting with anyone.
My friends and I were all stunned by this and I asked what made him think I was gay. He pointed at my hair and said that "only lesbians have hair like that" and to not deny it because I wasn't fooling anyone.
We all just stared at him in complete disbelief, even his friends looked embarrassed.
Here's where I might have been a dick.
I pulled up a picture of me with my bald head, looked him in the eyes and said "I used to be bald and my hair is only just growing back". He looked at the picture and said "why the fuck were you bald?" I just coldly looked at him and asked "why do you think some women become bald?"
Even though I didn't say anything else, and never confirmed or denied anything, I watched his and his friends faces turn from confusion to complete horror as they all came to the same conclusion.
They all though this guy was being a homophobic dick to a cancer survivor.
He started apologising profusely to me, telling me he didn't mean it, he had family who had cancer, and he wouldn't have said anything if he knew. I just replied "there's a lot of reasons women have short hair. Maybe consider them before you start being a homophobic prick."
His friends eventually dragged him away and kept apologising to me for him, but we decided to leave to avoid further drama. My friends decided to play along until we left, and we had a giggle about it afterwards.
I know it was wrong to make someone think I had an illness, and I have so much respect and compassion for those who have fought or are fighting cancer. But I hope that this guy thinks twice before berating a random woman based on her hairstyle, and that he learned not to judge others so quickly.
Edit: just to add this because I keep seeing people criticising my friends for not defending me.
They did try. We all tried to ignore him and tell him to leave us alone. He just refused to listen. We were all around 19-20 (drinking age in uk is 18 before anyone comments) and he was older and a big guy, plus he'd had a few drinks. I don't know if you've ever tried to tell a big drunk guy to go away, but it can be difficult and scary, especially if you're young and don't know how he'd react. I also remember his friends trying to get him to leave us alone, but he ignored them too. The entire thing only lasted a few minutes, and we left pretty quickly after. If it happened today we'd have no problem telling him to piss off, but that's the joy of being older and wiser.