These are some icks and some unhinged things he did. All tracksuit guy (dated on and off for around four years, he was 33, for reference, I was 26 when we split up for good).
He also had a gaming chair, which he sat in all day. He didn't really work, he just had this vague role with a guy who lives in another country doing web design stuff, he'd work for max 4 hours a week? And he'd spend all day playing league of legends, some civilisation game, or arguing on Facebook.
He had an especially awful mullet for around a year of the time we were seeing each other.
One time I left him, he sent around 50 messages to my neighbour/friend which were actually quite concerning looking back but also very embarrassing. At least she saw the funny side and remains my friend.
He was a super picky eater and that was his excuse for never taking me on a date. He'd eat chilli or oven pizza pretty much every meal.
He drank full
large milk? Not sure why I found that cringe but I did.
He called snacks "munch"

.
He took posed nude photographs of himself in black and white, he was very proud of those, in one he was posed like The Thinker but with one leg up. Instead of being turned on, I was drier than the Sahara...
He once got a CCJ and demanded I pay it off for him, I didn't and he threw a tantrum because he had to pawn his gaming PC.
The only furniture he owned was a sofa from his mum's, a bed, his gaming desk and gaming chair. Nothing else.
I told him my favourite colour was sage green, and one day he told me he'd painted his bathroom sage green. It was not sage, it was neon teal. When they got evicted (him and his weirdly codependent flat mate) for being too noisy, his landlord fined them for painting the bathroom.
They also didn't own a vacuum cleaner so the carpets were disgusting and I had to bring mine over to vacuum their flat.
Ultimately the joke is on me because I continued to see him despite all the above, but he had honestly ground down my self esteem to a point where I thought that was as good as it got. I am a single parent and had definitely found it hard to find good people to date in my league at my age, so was accepting all the crap from a loser instead. But I did end it after some gentle encouragement from my amazing colleagues (and less gentle encouragement from my parents). Seeing a very lovely man now who, so far at least, has not given me the ick!