Pedilia,
I'm pg now and so wont throw up at the moment, but prior to becoming pg, i'd do it as and when i felt like it.. sometimes regularly and sometimes not for months. I dont know what i'll be like after the baby, as the fear of not losing weight may get ontop of me, but i'll see how it goes. Either way, I'm no where near feeling able to see a doctor or to speak to anyone who knows me about it. (apart from dh). Its too much of a taboo to really speak about, and is very embarrassing to admit to doing something so vile. I am really hoping to be able to diet like normal people post birth.
If your dh is in the position where he is not able to come to terms with it, then i really dont think giving him an ultimatum will help. If it were me, and i were given an ultimatum, it would make me even more secretive and less likely to confide in my other half. I do think there is lots you can do to help.. my dh knowns my fear is piling on weight, but that i'm also a sucker for 'bad food'...(If thats the trigger, you cant cut out bad food altogether, as he will just binge to a greater degree on food he doesnt feel he's allowed, and then feel guilty, hence the purging) My dh will go to the gym with me to get rid of some of the guilt and will eat healthy stuff if i start moaning about feeling fat, which helps. I find if i'm feeling good in myself, and feeling healthy, I dont need to eat the crap... If i'm feeling bored/fat thats when i'd be more likely to eat loads, and then feel guilty about it. Its different triggers for different people, with me its a fear of putting on weight (having lost lots on ww), but an urge to still be able to eat tasty food. With others it might be something they feel they have control of.
I'd say that if you encourage him to talk about it and not seem too shocked or judgemental, you are far more likely to get him to talk to you about what makes him feel like doing it, which in turn you might be able to help with. Dont go listening at the toilet door for tell tale signs, or watery eyes, as it'll make him more secretive.
I'm really sorry its affecting your family... it must be really frustrating for you. I found it hard to tell dh what i was doing as its such a horrid/ disgusting habit.
Hope this gives you a little bit of help as to what may be going through his head... Fingers crossed for you x