My sister-in-law is a single mom and her adult son moved back home three years ago due to rent else being too high. He's 38 and she's 54.
She was a teen mom and the dad was only in the picture for the first year before abandoning them, then it was just her and the son living together. The son was always a moody, difficult little prick who threw tantrums constantly and pretty much did what he wanted. My SIL is a rather meek person, so aside from yelling at him a few times, never really stood up to him or disciplined him.
Luckily, the son has a type A personality and always did well in school, so he has a good career in the financial sector but has always stayed close to home for money reasons. He didn't move out until he was 25 the first time because he was saving up a nest egg so he wouldn't be living on a tight budget, came back at 31 to save up again, then somehow found a girlfriend to live with, then they broke up (this girlfriend ranted on facebook about him being a hoarder), and he moved back home again to save up money. Now, three years have passed and he's still living at home with the mother, saving up money to buy his dream home. He admits that he has no plan on leaving until he has every penny saved for his dream home because he doesn't want a mortgage.
My sister-in-law insists it wouldn't be a problem if they actually got along, but they don't have a close relationship and he always seems annoyed by her/barely talks to her. He's a messy pig who has destroyed her home, yet again. He leaves dirty clothes and dishes everywhere and refuses to admit they stink, so when she asks him to clean up, he stubbornly refuses and then she has to do it, otherwise the house will stink. He's a cheap-ass bitch who refuses to buy new furniture, so all his pieces are ancient, second-hand and they smell (mattress, bedroom sofa, curtains). The furniture, which he brought from his old apartment, smells like sweat, stale body odour. I've been to the house, and there is a terrible odour when crossing his room.
He plays loud videos up in his room---meditation videos and finance/politics videos. He refuses to turn down the volume. He drilled an exercise bar into a weak ceiling in the hallway, so now that portion of the ceiling if caving in--he's also damaged the walls in his own room, the bathroom and the attic. He uses heavy exercise equipment in his room and skips rope, weightlifts and kickboxes at night. It sounds like a construction site, with all that slamming and banging. He also plays tennis against the walls indoors and has put dents in it. The mother has told him to stop, that he's damaging the house, but he says it's not a big deal because it's his room and he sees no damage.
He has a rolling exercise wheel that he uses all over the house, so now the carpet is rippling up because of it. Because of this wheel, the carpet has bumps all over--the stairs, the living room, the kitchen. Aside from that, he's a hoarder, who has baskets of junk all over the house. He refuses to let her throw anything away, yells at her if she even attempts to move the junk out of the way. Also has a variety of junk in the garden that he refuses to throw away (scooter, an old metal shelf, an old kickboxing dummy) Within weeks of moving in, he planted a row of cactus trees, and refuses to let the mother remove them even though she hates them and constantly complains about them. She explained to him so many times that she doesn't want spikey cactuses infront of her doorstep because they stab her ankles but he does not care. He just insists they are his plants and nobody is to touch them. My sister in law chopped one down a few months ago when he was away on a business trip, and when he returned home HE WENT NUTS and punched a whole in the wall.
I'm rambling, but is this what happens when a boy grows up without a father? Do they need a male figure to put them in their place? Because it seems to me, these men just walk all over their mothers because they've never had authority figure say "shut the fuck up, you're the kid here, behave yourself."