mouth problems

In edit mode without subsurf the mouth looks like this.

When I click on subsurf the mout looks like this .

How can I change this right the lips are getting open in the middle?

do clipping

Thanks that works,
But now this happens with the chin ??
The chin should be nicely round.

Anton, I’m a newbie … but when I looked at your .blend file … I think I found that the two halves of your face were already joined. Swith off your mirror modifier and you will see that the second half remains. When I switched that off, the bumps on the chin went away.

O thanks that must have happend when I add clipping on
then choose apply and suddenly the modifier mirror disappeared.
So I put a new mirror modifier.

I started to model a new face.
This time I started with the nose instead of the whole face from a cube.
Modelling now with subsurf and mirror modifier on.
Still got a lot to do so lets play blender again.