He is at it again....

Yesterday I was working with him (we had a nice little chat the other day and cleared the air - or so I thought). And he says that our advisor is letting us down. I asked how he was letting me down. He said that our advisor should have stood up and told me my most recent experiment was "worthless". Yes - he called my experiment worthless.

I told him that it was exploratory and you have to do little things that don't work to know what to test. What I am working on - nobody knows anything about. So everything we do is brand new. Then I told him that it goes both ways and I don't really understand what he is doing and don't get why he does certain experiments but it's not my place to say anything.

I told him that we (our advisor and I) had already talked about it and he told me "that's fine if it doesn't work. I am all about exploratory experiments". This thing took 4 days total and cost no money whatsoever. So, to me, it wasn't a big deal if it didn't work. But he insists that it is "worthless".

I said "aren't you supposed to be done in December?" and he just said "technicalities". I really am just sick of this. If he thinks our advisor is not doing his job and he wants to sit there and talk crap about him - why would he want to stay? Where does he have any right to diss my experiments and tell me what I'm doing doesn't matter? He isn't in our meetings. He doesn't know what we talk about. He has no idea what we are trying to get out of this or the fact that YES I DID FIND SOMETHING NEW.

I told him that, after I calm down, we need to talk and that I have a lot more to say to him. I feel like just writing a letter so I don't forget anything - plus I'm not good with confrontations. But something needs to happen. He is just getting out of control. He is talking crap about everyone - in front of the new students, too. He has no right to say anything about the man getting his funding and paying his paycheck.

I feel like our advisor has a right to know what his own student is saying. I feel like he wouldn't be so ready to take him on as a PhD if he knew the kind of things he was saying to his other students - and about him nonetheless. But I don't know at what point to open my big fat mouth. I am really having trouble seeing the line of where to step in - if stepping in at all is appropriate. Before it wasn't affecting me personally but now he is flat out calling my stuff worthless - and to others that I have to work with on a daily basis. And he is talking about our advisor in a negative way - and saying these things about our dept. head as well. Is it even appropriate to say anything to my advisor?