Knock Knock

The kids like to tell each other knock knock jokes. A couple of nights ago, they started off making sense and somehow slid downhill...

1st joke - told by Haley
knock knock
who's there?
who
who who?
stop talking like an owl!

2nd joke - told by Preston, trying to copy Haley's joke
knock knock
who's there?
an owl
an owl who?
stop talking like an owl!

3rd joke - told by Brekken... apparently trying to tell a joke like the last two
knock knock
who's there?
pineapple
pineapple who?
stop acting like a pineapple!