Thanks Perna and AAAAA for your thoughts and advice. I do really think she needs help and I have nothing against helping her, but do you think I should involve myself more in this or just let him deal with it?
I'd like to know what's happening, I think that's more what is annoying me in this. Being left in the dark, it makes me feel like I should make the most of the moment until her next panic attack or suicidal thought.
Perna, I'm not comfortable with giving him an ultimatum to finish it because supposingly there is nothing to finish and I know him, I know he's not playing with my head or hers, he's trying to avoid trouble but I guess very passively which in the long term would make it worse right?!
This is hard to confess and I feel very bad about it, but I've checked a few of his messages and that is how I know she still contacts him and he ignores her by lying to her with stupid excuses rather than just telling her to leave him alone or that I'm with him. I should say that earlier in our relationship, she knew I was with him that weekend and she called to say she was depressed and thinking about doing something to herself. He had to go and leave me then. So there is this risk that if he told her he was fine and happy with she might threaten to do something again, which I don't know how to get him to consider that it could be just manipulation.
I love him so much and don't want to loose him and sometimes I think he feels bad or guilty for having found himself in this situation which makes me want to be there for him even if it hurts but how do I get him to realize this is serious and he can't just wait until the next suicidal call! and how do I do it calmly without getting myself heartbroken too.
Many thanks for both you Perna and AAAAA, I feel much better getting this off my chest, I'll try to check some professional help around and suggest it to him in some sort of way. But if you have any more comments please keep them coming.

Thanks loads
Espoir.