I finally left my ex about a year ago, it's taken a while to realise how much of a bastard he really was
Having read a few pages of the original 'red flags' thread, so much of what everyone says applies to him.
When we met I was 16, he was 25, I'd never so much as kissed anyone before, and he seemed very grown up and experienced.
He smoked an increasing amount of weed throughout the relationship, starting at about £40 worth a week and ending at about £60 worth a day, meaning that we had to scrape together spare pennies (literally) to buy food with. His mum gave him money (about £300-400 a week!) and paid all his bills.
So much sulking! He sulked if I refused sex, even if we'd already had sex more than once that day. He sulked when I went to see my friends, and accused me on numerous occasions in very graphic detail of having an affair with my best friend, who is a straight woman with a boyfriend. He sulked when I went to see my mum, or wanted to talk to her on the phone in a different room. Always wanted to know what I'd been talking about with everybody else I ever spoke to. When we lived together, which we did after being together for six months, he wouldn't let me sit in a different room from him and if I did he'd stomp about slamming doors and sulking.
Always made me feel like I was too boring for him, told me I was "vanilla" because I didn't want to have anal sex or smoke weed.
Showered about once a month and then still expected blow jobs and would sulk if I didn't want to, talking about "resigning himself to a life without blow jobs" 
Said he loved me after a month, told me frequently that he'd probably kill himself if it wasn't for me.
Could never drink without being so drunk it was both embarrassing and a bit scary and then passing out.
Told me he hated all my friends and the 'scene' they were in, once said the words "I think about you having fun with your friends and it makes me feel sick", would accuse me of "always going out" when we lived together and I was going to see my friend once a week.
Never hit me but would often throw things at the walls/throw things (like clothes) at me/ follow me round our tiny flat shouting, once kicking in the bathroom door that I'd locked to get away from him.
Accused me of laughing at him every time we argued, until eventually I did start laughing during arguments in a horrible nervous sort of way, then would tell me I went out of my way to make him feel like shit. Also, his response to every argument was "I guess I'm just a cunt".
After we broke up, he spent a few weeks alternately calling me a cunt and telling me I should get psychiatric help because I'd made up problems in the relationships that weren't there. Recently sent me an email to tell me "I've been thinking, and all the reasons why we broke up were your fault"
and "I'm not going to let you treat me like shit anymore".
Well, that was quite long, but cathartic 