What have I done. . .

Okay. Firstly I am shaken and traumatized to the full extent. Firstly backstory: My friend is leaving for a few months and he asked me to take care of his cat for him because he could not take her with him. Of course I said yes because he really needed the help. It was me or a pound. So I had the kitten meet my pupper who is very kind and gentle and has never shown a mean streak. Ever. And it was fine. But the thing is I have 2 puppers. The kind one is Tate but the younger one is Coco and I wanted to keep coco as far away from the kitten as possible. He didn't like her and he was troublesome whenever she was around. So I kept her in the room and my 2 boys in the living room.

Now to the worst part.

I keep coco the baby husky in the cage when I leave because he chews on things and he isn't potty trained which isn't my fault because the people I got him from didn't have him on a schedule so were trying but he always seems to find a way out so I've been blocking the door with a dresser so he can't get to her. The one day I didn't because he never seemed to try to go for her anymore I come home 5 hours later to a dead kitten in my bath. I am so shocked and saddened. I haven't told my friend yet because he would be devastated so I just bought a kitten that looks just like his and I've been saying that its his. And he hasn't noticed a difference. Should I keep lying or let it be? He's had this cat for almost 10 years and I managed to murder it in 4 days. What do I do??