[ A couple weeks. Stiles kept his cat in the down for... quite a bit longer than that, but the only reason they ended up adopting her officially is because Derek gave the okay and kind of insisted that they shelter her from the life of being a stray. He'd projected pretty hard onto ol' Nameless, empathizing with her in a way that made him want to keep her, but - he doesn't really need to project his own bullshit onto Cobain to care about her. The guilt did enough of a number on him already.

D'you got competition, Tate asks, and Derek levels him with the most unimpressed stare imaginable. ]

No. Only thing I'm going to have to compete with her for is your attention.

[ And, like, the bed. He's already been kicked out of his own by Stiles' stupid thing. Derek drags his eyes from Tate to the open roof, looking for signs of Cobain. He breathes in, then out. ]

If you had told me about her sooner, I could have helped. Brought some blankets out from the den, or... something. I've literally got cat food in my kitchen going uneaten.

[ Because his cat only likes fish, the cliche little thing. Stiles' cat, he means, not his cat. Definitely not his cat. Derek looks back to Tate. ]

Keep her. She can stay in the treehouse, if I haven't scared her off. I don't mind.