secret shifter Danny (ferret?)

[cats-whiskers0.livejournal.com]

This is nagging at me - this is M/M Steve and Danny and is at LiveJournal and AO3 I'm sure - Steve gets huffy because they have great nights except Danny always leaves and goes home. Steve wants Danny to stay and he does, but Steve realises that Danny is lying to him and is not sleeping. It turns out that Danny shifts into a ferret? Stoat? and Steve wakes up one morning to find it curled up next to him?