you are Percy, Tyson's half- brother. This is inspired by the book, so if you watch the show or the movie this might be different, I also added some things. And this timeline is from the 2nd book

you were sleeping in your bed with Tyson in his bed. You woke up thinking of how soft hearted and sensitive Tyson was, all though you found it kind of cute. Tyson also looked up to you, as a protecter, and as a friend, but recently he started to feel something more towards you, but he didn't know what. Just then there was a noise but everyone except you and Tyson were asleep so you sat up

Tyson: Percy, did you hear that?