I (42M) have been with Anna (39F) for four years. When she moved in three years ago, she brought along her two sons, Nathan (16) and Chris (17). I've never really had a problem with them, as Anna raised them well—they are generally respectful, know how to make a decent meal, and are willing to come to me or Anna for advice or emotional support.
The problem started the last year or so. When Chris graduated, he didn't really have a plan for "after". He did a little course upgrading, dabbled in a few college classes, but more or less took time to enjoy days off and figure things out. Unfortunately, by this point he's 20 and still doesn't have any kind of forward momentum in life.
He spends most of his time in his room, playing video games or sleeping for over 12 hours a day. The only time he really leaves the house is for going out with friends or his dad. He says he has no energy or motivation to do anything, which I know are symptoms of depression—but he won't take any help or advice from us. He seems content to wallow in it without taking even baby steps to gaining independence or mental wellness.
He's also a master of learned helplessness, probably taught by his dad. He'll call me in the middle of my work day to ask what to do with someone else's finished laundry, how to mop up spilled water, or what spices to put on the chicken he's made before. If asked to do the dishes, he will run the dishwasher but ignore wiping down the counter or collecting dishes from around the kitchen. Every step of every task has to be repeatedly prompted, no matter how often he's done them. If not, nothing gets done because he has no instinct to see a mess and take two minutes to clean it.
He's also been "job hunting" for two years, though both Anna and I are skeptical of how much he's actually doing. He has an interview or two every few weeks, and while I know that the job market is generally slow, there are dozens of help wanted signs all over town. His brother found two part-time jobs in six months. Chris hasn't had a single offer.
The more Anna and I try to encourage or convince him, the more pushback we get. Consequences for things like staying up late shouting at games or not completing chores are impossible to enforce, because "Dad will give me money" or "I have unlimited data on my phone that Dad pays. ¯\_(ツ)_/¯"
It got to the point last fall that we decided the only enforceable consequence would be eviction, so we made up a contract that he signed. Basically, it boiled down to these points:
Find a job or go to school full-time.
Pay a small "rent" to help pay for food and utilities.
Do x (specific daily chore) every day.
Respect quiet hours consistently.
If he didn't meet those conditions by June 1 of this year, he would be out.
The first few months, it worked! He was much quieter at night, he was getting at least an interview a week, and he even paid his rent on time. But then things started returning to the status quo. Now, a month from the deadline, he rarely does his chore and heaves dramatic sighs whenever we ask him for any other help, has had maybe one interview this month, and quietly stopped paying rent without a single word to me about it. The last I heard, he's made a vague plan to go back to school in the fall.
While I know it's hard to drag yourself out of a rut without support, I feel that Anna and I have done everything we can. The plan to go back to school feels like too little, too late. There's been almost no visible effort since the new year, and at this point we're just kind of done. He has the option of moving in with his dad, but I'm pretty sure that it would end in tears or even worse habits being built and encouraged. He doesn't have the skills or knowledge to figure out what to do on his own, but I can't keep letting him stay here.