An ex boyfriend was an appalling sulker. He would get into arguments with bar staff / bouncers so we would have to leave (if I was having fun).
I was 18 and due to go to university and he sulked like fuck about that.
He moved up to my university and we lived together. Then he would sulk because he had moved (his decision - he got made redundant at his old job).
If we were out on a night / day out and he had decided to sulk, he would walk reeeeraaaalllly slowly (to the point of being uncomfortable) and shuffle his feet about.
He would ring me at university and, if someone else picked up, would just sit there, sulking and not say anything. He stopped when I told him we were getting some creepy silent calls and one of the girls had spoken to the police (I had no idea it was him at the time).
I had a few thousand and he had a business idea. He sulked because I didn’t just hand it over to him to start the business and said that he had to get advice / a business plan.
He did a masters after he got made redundant from the next job. I leant him some money to do the masters (I know, ridiculous). I then said he should think about applying to some jobs and he sulked because he’d passed the deadline for a few and I’d applied months ago.
In the end, I had some professional exams for my first graduate job out of university. He didn’t like that so he broke up with me a week before the first one. He then tried to get back together with me the night before my last one and was SHOCKED that I said no.
The funny thing is, the next girlfriend he had basically dumped him for being a sulker. Good for her, I should have.