how do i help my friend overcome his bulimia and problems?

i was searching the internet looking for answers and found this site, which has impressed me, and hopefully some here can help me find the answers what im looking for. this is a totally complicated bunch of issues, and any help or advise is extremely appreciated. its a long story, but its at its climax now, and i need to sort it.

from the ages of 12 to 14, i was really good friends with this guy called Liam - he was basically my best friend in school, but we didn't do anything away from school together - we had separate friends for that. Anyway, in school there was 3 of us, me, Liam and Marc, and ultimately groups of 3 don't work, i felt pushed out and ended up starting on Marc, who Liam took sides with - so we all fell out.

fast forward 3 years to the age of 17 - and Liam being 18 - we ended up making it up and now hes my 3rd best friend in the world, and his best friend is also my 2nd best friend (and Marc is out of the picture).

Now, it was last October when we made up, and it was strange talking to him again, but i soon relaxed. But when we first went out clubbing together, he told me he was Bulimic. i knew this was a very serious condition, and i myself have self induced vomited food i shouldn't have eaten, but when i talked to his best friend - Jade - the next day, she told me it was sorted and hes over it, and a few people know. Well, the night he told me, he had just made himself sick to get the alcohol out of him, so he could consume more. i knew then he wasn't over it, and i just let it go by, because who was i to interfere - id only known him for 3 weeks (we are different people to who we were back when we were 12 and 14, so i class it as being a different person im now friends with).

Now, i came out as Bi in august last year, 2 months before me and Liam made up. Since we made up... ive kind of had this thing for Liam. totally inappropriate to fancy a friend but, i cant help it. Plus, ive always suspected he was Gay, but in denial.

Why do i think he is gay? Well, in some ways hes very stereotypical of a gay guy. He loves Cher and Britney very much. He loves clothes. He is obsessed with working out to get the 'ultimate' body. When we go clubbing, he loves all the old gay anthems, and learns dances to songs such as 'Toxic' and 'Lose my breath' before we go out, and does them in the night club. He has this thing about Marilyn Monroe.

And then there is the 'strange' things he talks to me about: Everytime we go to the local pub he always asks me about my gay sex life, and never about my straight sex. for example, he wanted to know everything about my first gay time, which lads in our college id do, which celebs would i love the night with etc... and even last night when we were in the pub, he was asking how and when i knew i was Bi, and what its like to do things like anal with a guy etc... put politely, he wanted to know the ins and outs of my gay sex life, and seems fascinated about it, something strange for a 'straight' guy.

And then there is the incident last week.

I had a group of friends over - and were all fantastic friends to each other - i hide nothing from any of them. and Liam got drunk on a bottle of jack daniels. to cut the story short, he announced that he was Bulimic to us all (again) and he went to take off, but we stopped him, saying his taxi would be here in 10 minutes (which was true). well, he didn't like that, and started saying to us, 'you don't know what its like to be 'that' for 4 years' (he wont say the word bulimic), and in the end he picked up a knife, which took 4 of us to get off him. its the first time he's used his physical strength against anyone to get his own way, and he was not letting go of the knife - thank god there was 4 of us because the 3 of us wouldn't have been able to get it off him.

anyway, we did, and i called his mum - and told her everything.

But since ive been doing research on bulimia because its evident hes not over it, and one thing that has come to light is that food isn't the cause, and its normally something completely unrelated.

it could be the desire to stay thin because he used to be fat before, but when ive talked to Jade about what it is he cannot face up to, she told me shes thought for some time it might be the fact he is gay and cannot deal with it, which i found strange, but true, because at the end of the day he knows i kept it hidden for over 5 years before i came out, which ive told him depressed me, and was the reason i was so fat before hand too.

And another thing that came to light is that before he grabbed the knife, we were playing truth or dare, and the dares were determined by this body dice i got, which shows a picture instead of a number of a part of the body. well, Liam seemed up for kissing anyone, including me (which for a straight guy would have traditionally been a problem), and he also let me kiss his ass (there was forfeits, but he opted for the kiss). and also, he told Jade completely off topic that 'she didn't know wat its like to be always told your gay, you dont know what its like' - the first time hes said that to her.

So, basically, thats the lot, but i dont know what to do. if it is that he is gay, and cant deal with it, his bulimia will get worse and next time we might not be able to get the knife off him. and the only way he can deal with his bulimia, is if he admits to himself and others the reason why he developed it. other than ask him out right if he is gay (which he would deny to me if he was - instinct) theres not a lot i can do for him, but what if he realises that i think hes gay and that kicks off his bulimia again? hes already told me that the urge to binge and vomit is back. i dont want to be responsible for that either.

does anyone have any advise?

thanks x