I see one or two men "spread" every day on the subway in Boston. Some even do it while someone is seated next to them, forcing their neighbor to sit sideways or be squished. The subway seats are narrower than they ought to be, and many people simply don't fit, but spreading is an act apart.
Never have I seen a woman sit like that on the subway. Granted, it's possible the reason women do not do this is merely one of propriety or upbringing and not conscientiousness. Likewise it's possible the reason men do this is merely obliviousness and not inconsiderateness, posturing, or entitlement. But it is absolutely a predominantly male behavior.
I see it nearly daily on trains in Brisbane. I also see idiots "manspreading" about as often. Shit people are shit people.
I don't think it's a problem that needs to be solved. Imagine if your discomfort was visual: you're walking on crutches or you have a cast. People would naturally give you more room because they don't want to cause you any pain. Men are not about to say, "excuse me, ma'am, my balls are sweaty and it's not appropriate to adjust them to a certain degree in public, and besides that I don't want to crush them between my legs, so if you don't mind, please forgive me if I take up a bit of room on the seat."
In reality, men manspread because they can. Spreading out your body to take up more room discourages someone from sitting next to you. This includes spreading out your shoulders and keeping your arms away from your body too. Most men, if confronted, will defend the practice by saying that they'll move if someone wants to sit next to them. But, though they may not want to admit it, they know that they're intentionally discouraging anyone from sitting next to them, and that most people on mass transit will choose to stand rather than ask a complete stranger to stop hogging the seat.
[1] Under normal circumstances. I'm sure there are medical reasons why someone might have overly tender testicles and experience discomfort doing this, but for the purposes of this conversation we're talking about people without any medical issues.
> If you want to sit next to a guy spreading his legs, simply ask him to move over.
That is not an acceptable response. It's a fact that people in general do not feel comfortable talking to strangers on public transit. And it's especially true that women do not feel comfortable confronting strange men. Add to that the fact that everybody can be expected to understand that taking up a seat with their bag is rude, so nodding towards someone's bag as a way of asking "can I sit there?" is acceptable, but most men don't recognize that manspreading is a problem, so you can't just nod towards a seat to mean "can you please minimize your personal space so I can sit there?". You'd have to actually talk to someone, explain that they're taking up too much space, and hope that they don't react poorly to this. This is just not something you can expect people on public transit to do to complete strangers in general, and especially not something you can expect women to do to men.
Manspreading is pretty much exclusively a male problem, and "just ask the person to move" is an example of male privilege. And it's been going on long enough that apparently we do need to keep bringing this up over and over again in public discourse in order to get men to even recognize that there is a problem, much less work to fix it.
Everyone has privileges in life and everyone has disadvantages. Making this an issue about gender hurts everyone. When you hold the group responsible for the actions of individuals in that group, you risk "tribal" war.
Ask the guy to please make some space for you, and move on with your life.
Instead of trying to pretend this isn't an issue and making excuses, maybe you should actually listen to all of the women who have had to deal with manspreading. And maybe just start paying attention the next time you're on public transit, any time it's not 100% full already, look around to see just how many men are spreading. Heck, even when it is 100% full, look around for any time you see a woman sitting next to a man and compare how much physical space they're taking up. Even when all the seats are full, men still manspread, and women end up having to minimize the space they take up as a result.
> Ask the guy to please make some space for you, and move on with your life.
This is a perfect example of male privilege.
I am a woman.
If a man is taking up too much space and I want to sit next to him, I ask him to move over. Never had a single issue.