I love you the mostest - If you say 'I love you the mostest', you're basically saying

If you say 'I love you the mostest', you're basically saying you're the love champion and no one can top you.

He said I love you the mostest and she just had to accept it.

They were arguing, and he said I love you the mostest and she gave up.

He messaged her: I love you the mostest. She replied: You're the love champion, but I still love you more.