I'm not sure if this belongs here or in the da
ting section, as I'm not the one in the rel@tionship. Please move it if needed.

BG: Jill is my best friend. I introduced her to an acquaintance of mine, Jack (he was in the process of joining a club I'm president of), several months ago and they hit it off big time. They've been a rel
ationship for a few months now and they're even talking of moving in together. So it's serious.

I'm happy for them both. And Jack has become a friend of mine and DH as well. /BG
Recently Jack has been putting a lot of pressure on Jill to move in with him. Jill is a little hesitant of moving for several reasons (most of them having nothing to do with their rel
ationship; financial, logistical, etc.). Jill asks me for advice sometimes and I'm always careful not to tell her what to do, but give her ideas that will help her make the choice on her own, deciding what's best for her. Jack confides in me how much he wants Jill to move in, to which I usually respond that he seems to be putting a lot of pressure on her, and could backfire on him. He seems to be annoyed that I'm not telling Jill to move in with him right this second. So I think that's some tension he feels towards me that's been brewing. Additionally, Jack has been under a lot of stress at work.
Well, recently Jack and Jill have been having some fights, as have DH and I, meaning that Jill and I are spending a lot of time together confiding in each other, asking for advice, and comforting one another, usually in the form of phone calls. DH is fine with this, as he know it helps me feel better and ultimately work things out.
Jack on the other hand, has been privately lashing out at me for "clinging" to Jill so much. He accuses me of hogging her time and treating Jill like my husband. He even told me I should "focus more on [my] marriage than on Jill," which I felt was pretty rude and condescending. He says I'm getting in the way and I need to back off. I basically ignored these remarks and walked away from the conversation because I think that Jill and my friendship is not Jack's business, and if she wants me to back off, she will say so. Furthermore, I think some of this is misdirected anger and Jack is using me as a scapegoat for his rel@tionship problems. DH thinks that Jack is jealous of Jill and my close friendship.
I have not told Jill about the things Jack has said to me because I do not want to poison her view of Jack. I try to be impartial when we talk about their rel@tionship, and I don't want to sway her to do anything rash because of something I said. However, I do want Jill to say if she wants more space. We are both fairly timid and can have trouble expressing what we want sometimes. I sent her a text message saying, "If I've been too clingy, I apologize. Just let me know if you need some space." She hasn't replied yet.
Am I handling this okay? Should I just continue to ignore Jack? Would you tell Jill what Jack had said?