I manspread on planes — I don’t get why that’s a problem

The rules of flying can be difficult to navigate — and one man’s admission of purposely “manspreading” has added jet fuel to the etiquette fire.

A man, who said he was 26, took to Reddit to explain his situation, claiming that he was on a six-hour Spirit Airlines flight and sitting in the “middle seat” between two women.

“I’m tall and am never comfortable on planes,” he admitted. “My knees always dig into the seat in front and it can be quite painful.”

About a half-hour into the flight, the passenger confessed that his knee started to inch to the left, “level” with the shared armrest.

He said he wasn’t paying attention the whole flight, so his legs may have spread out over his neighbor’s space.

“I’ll concede it’s possible that at some point I was occupying space that rightfully belonged to my window seat neighbor,” he wrote.

The flight was fine for the first couple of hours until the passenger near the window called a flight attendant over, reportedly asking her to order him to “keep his f–king leg in his own f–king seat.”

He said he felt “deep shame” at the altercation and “instantly retracted” his leg.

He then claimed he tried to apologize to his seat mate when the flight staff member left.

“She refused to speak to me,” the appalled man wrote, recalling that the woman was “furiously texting” instead of acknowledging him.

The person on the other side, in the aisle seat, told him she had some extra space he could use, but “promptly went to sleep.”

The Post has contacted Spirit Airlines for comment.

“[The woman on the window seat] ignored me the whole rest of the flight, and I ignored her,” he concluded the post. “I got a good but painful workout of whatever muscle it is that keeps your knees together.”

His post infuriated users, who slammed him for his ignorance.

“This is a known, recurring issue,” one Redditor wrote. “You KNOW you will feel better with more leg space. Stop pinching pennies and pay for an aisle seat or an exit seat. There are options!”

“You have no right invading someone else’s personal space especially when the space is rather limited and it belongs to a stranger!” agreed another. “You should of paid for the extra leg room sit.”

Jacqueline Whitmore, a longtime etiquette expert based in Florida, told Fox News Digital that proper airline etiquette means that you “keep your arms and legs to yourself.

 “The seats may be getting smaller by the day, but that doesn’t give you the right to spill over into someone else’s space or put your head on another person’s shoulder,” she explained. “Unless, of course, you know that person well.”

Last November, Reddit user Emily Kauai divided users after posting a photo to Reddit of her experience during a four-hour flight last year.

The picture, which has generated more than 6,000 comments, showed the man next to her sitting with his legs spread, leaving her with little space to sit.