Excuse for having your phone upstairs?

Hi,

My dad always wants my phone downstairs in the evenings. I think that's stupid, and if he doesn't tell me specifically in the evening, I always take it upstairs. He just came into my room and looked under my covers to see if my phone was there. Then he asked me where it was, and out of panic I said downstairs, even though that wasn't true. My mom is coming upstairs now, and I think my dad is going to ask her about it. She'll either say it was in the kitchen, or that she didn't look.

I was now planning to secretly take my phone downstairs.

What should I say to my father tomorrow when he asks why I secretly brought this downstairs at night, etc.?

Please help me