"They can hear you." Istredd reminds him, since they are in fact babysitting at the moment, although then he glances at the kids and it turns out they are not, in fact, listening. So Lucifer's veiled (and untrue) threat doesn't concern any of them.

If he gets a fungi doll he's going to throw it at Lucifer's head.

Istredd is gentler with them, unsurprisingly, even holding hands or delicately placing a hand on their backs to guide them. He may only appear to be better at this than his partner, he also is not great at it. This is why he's glad 'their kids' are teenagers already. Not that it doesn't have its own downsides, but a sassy teen is not the same as a possessed child.

Istredd pauses at the suggestion and sighs. He can't argue with the idea of testing out what happens. This is experimentation after all, and he needs to know how they react before figuring out what kind of curse this is.

"You need to pay attention, let me hold onto your doll for now, okay?" Istredd cringes because he can guess at what's coming next, but this is logical, it must happen. He picks the doll out of their hands and true to form, the child freaks out.

At first, she just panics and starts grabbing at it back from Istredd's hands, no sanity in her gaze. "It's mine!" She screeches and practically tries to crawl up Istredd's body to get to it. He holds it over her head, mildly panicked himself.

"Lucifer, help." Yes he needs help from the child, especially if they're going to study the doll, which they need to do!