Which one is OK?
I am eating cake right now.

If I say;
It sticks to the roof of my mouth.
It's sticking to the roof of my mouth.
It has stuck to the roof of my mouth.

Question

Which one is OK?
I am eating cake right now.

If I say;
It sticks to the roof of my mouth.
It's sticking to the roof of my mouth.
It has stuck to the roof of my mouth.

Answer

The second and third are good but the one to use would depend on whether it is happening now(second) or has already happened(third). You would use the first one if you were talking about cake in general.

Answer

It is happening now (mid-action).  So present continuous - It's sticking to the roof of my mouth. https://www.ego4u.com/images/grammar/present-progressive-1.en.png