Unemployed Boyfriend?

So here's my problem:

My boyfriend is twenty and lives at home with his mom and two younger siblings. I'm away at college so the only time he and I talk is over the phone. For two years he went to another state for a summer job where he saved a lot of money. Here at home he has been unemployed for a long time and I've brought up employment multiple times. I know he's got money, but for some reason I can't stand it that he just doesn't work. Finally I got fed up and said if he didn't have a steady job by my winter break, then I'm done. I love him but I need to know he will work! And why wouldn't he just get a job if I say it's important to me?

Anyways, he told me he got a job so aside from asking how work was every now and then I dropped the subject-- remember, I'm hours away, so all I have is his word and I trust him. The problem is when I came home for my break, my older sister and mom sat me done and told me that his mom said he quit within the first week (our mom's work at the same school so sometimes their paths cross). The problem is I don't know if I can trust his mom-- she's lied before. My boyfriend doesn't talk to her, and he could really be working and she doesn't know.

How do I talk about this with my boyfriend? He's never lied to me but he also never talks about work and whenever I ask how work was he drops the subject fast enough by saying "work is work". When my sister and mom talked to me, all I could say to counter anything was, I trust him. And the look they both gave me made me feel like an fool. Is it stupid to just trust him on this? The job he says he's at now he doesn't work that many hours, would I be out of place to ask him to work more? Am I being stupid for wanting my guy to show some initiative? How can I feel more secure in his employment situation without making him feel like I can't trust him?

Thanks