It is indeed a bit childish. The mouth shape of the flute is pulled to both sides. It is impossible to say that the lips are thickening. There is no basis for the theory that the lips are thickening.
As for brushing your lips with toothpaste, there is also no basis for it. Don’t believe such unreasonable rumors or folk remedies. The shape of your mouth is only affected by the bite of your teeth. This method is absolutely impossible to change. of.
My personal suggestion is to get plastic surgery.