I usually hang out at my friend’s apartment and he lives with another dude let's call him Billy. So Billy is a douche who loves confrontations and uses his ex-girlfriend, who still has feelings for him, just for her money. I was at the apartment yesterday and he was drunk and fighting with his ex and then he twisted her arm I of course intervened. After knocking him down in the kitchen and calling him scum and said he never deserved his ex he threatened to drink bleach.

I simply watched him as he took the bottle from the cupboard but he chickened out at the end. To be honest in the state of mind I was in I probably would have let him do it. It's only after the fact that I'm thinking would I have got in to any trouble if I let him.

No it is not.

Legally, I don't think so. I'm not sure though.

Morally, it depends on the person I guess.

Sounds like it was wrong of you to let him chicken out.

Depends, I suppose. If you try to talk someone out of killing themselves then yeah, do it. It is unlikely to cause you any physical harm.

On the other hand if a person put a gun to their head with the intent of blowing their brains out why should you risk your life physically trying to restrain him or her? The way I see it if that person is willing to take their own life he or she wouldn't think twice about taking yours as well.

Then again what is the person trying to top themselves to you? Relative, friend, someone you don't really know....
It all comes into it.

Only if you wouldn't have called an ambulance after he drank it.

In my opinion at least. Is it morally wrong to let him do whatever he tried to ? Probably yes, but I'm not going to judge you.

There's morally permissible and then there's morally optimal. Quite a few moral codes would find allowing somebody to kill himself permissible, but pretty much all of them would agree that stopping him is morally optimal.

To put it another way, it's not wrong if you don't stop a suicide, but it's most right if you do.

As long as a person is sane and not making decisions out of impulse or irrationality, I wouldn't say its your duty to stop them. For instance, in many cases, I think Euthanasia should be allowed if the person involved genuinely decides it is what they want.

In your case, you probably should have told him to stop acting stupid and grow up. He was acting on his anger and would have regretted it.

There is no such thing as an absolute moral code.