You weren't a normal person.You had powers.The power to turn into any animal you wished,which was pretty cool.Even tho you kept it a secret from everyone,including the Avengers.

You liked the Avengers.To some extent.Some of them came off as cocky to you.Unaware to you,Peter (Spiderman) was in the same school as you,so definitely had been noticing some subtle things that you had been doing.Subtle things that may have given away the fact that you had powers in the first place.He would notice things like,you changing your fingers into claws or other things.

He obviously wanted to tell the Avengers that there was a super powered person in his school.And that's what he did.

Now it's the next day and everyone was in science.