Why would my friend keep saying they'll see how loyal I am?

Recently my girlfriend and I bought an apartment together. This friend of mine is my housemate also, so he knows I'm moving out soon. He keeps saying we'll see how loyal I am as a friend. He'll tell me I'll just disappear and he'll never hear from me again. I'm starting to find this behaviour very strange.

One day as well I was reading an email on my phone. He asked me what I'm doing. I responded with just reading an email. Then he responded with " so you aren't going to tell me". What is this behaviour?

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But there has been other issues. Like he spoke to be reality badly. So I pulled him up for it, then he twists it back on me saying it's my fault. What I said wasn't even bad at all. Then he claims he can't be himself around the house and it like stepping on eggs shells. I literally just go about my daily business etc
Why would my friend keep saying they'll see how loyal I am?
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