You've hit on one of the major differences in the sexes: men solve their problems by disappearing into their caves and mulling; women talk to whoever will listen; we don't want a solution from them, we just need to talk it out. Once we realise that their silent treatment (problem solving) is different to when we use our silent treatment ('poor me'), we can approach the situation from a positive mindset instead of a 'presumed guilty by ourselves' one. Also, he may not know that he is problem solving, as it could be sub-conscious; unknowingly distracting him and making him feel low. Realise the difference and give him love and space.

Shocking him may work a few times, but after being with him for a while, he just may need to take his time to think things over before he talks about it. It really is a big gender communication difference. If you try to pressure him to talk, he might get mad. If you just tell him to come talk to you when he's ready, he may take 3 days. My suggestion is to set up a time to talk about it where he has more time to think but won't try to blow it off and hide it away to let it fester up.

I found is write a note (usually before I got out to my friends or out for the night) and leave it with him, with a pad of paper&pen, tell him to write whats wrong down as its easier to express your emotions abit easier than talking sometimes. That way, he can mull over it, sulk, have abit of a temper tantrum and you're out the house or way, so you dont get involved, and hopefully by the time you get back several hours later. He should of wrote down whats wrote, calmed down so he may talk about it, and put his moody pet lip away. Otherwises you could try, the whole "Dont say its nothing babe, I invented that excuse and it doesnt work *giggle*" Grab his hand, guide him to the sofa and say look babe, talk to me, I hate hearing my snuggle muffin upset. haha

Tell him the blunt truth. You know theres something wrong and theres no point denying it and pretending there isn't. And he'll be shocked at your bluntness and have to say it.

On the other hand he might just need his own space for a bit. It doesn't mean he doesn't love you, but we all go through phases. Many women are so clingy and demanding that they bug the hell out of their men and eventualy drive them away. Give him some space for a while (without sulking) and if he doesn't cheer up or give you an explanation for his moods you may start to wonder if you want to be with him after all.