A friend of mine, let's call him Bob, is in a relationship with a girl, Sarah. He is 24, she is 19. They live together with her 4 year old child. They often struggle financially and I, as I'm better off financially, try to help where I can.
Sarah has now repeatedly asked me for help with Bob, as he is reeeeeeally lazy. He does next to nothing in the household, leaving all chores to Sarah.
When she brings up specific things she told him to do, which he didn't, he gets defensive and offended. We're talking about small things here, like washing some dishes, close the shutters etc.
As if this wasn't enough already, he tends to be manipulative, trying to make her feel guilty for pressuring him.
For the first ~10 months they lived together, he didn't have any money and did not try to find a job or anything. He really hasn't got his life under control. Luckily, he has got a full time job for about a month now. She lives on welfare as she has to take care of her son.
I think his behaviour is unacceptable and needs changing, but I'm reluctant to speak to him, as I'm afraid he will just get offended again and nothing will change. And even if I get him to agree with me, the past has shown that this will not help much and not for long.
How do I tell him that his behaviour will cost him his girlfriend, in a way that he will at least try to act on it?