De or het slobbering?

The correct Dutch article is:

de slobbering

Rule Words ending in -ing: almost always de. See the rule

How to use slobbering

the slobberingde slobbering
this slobberingdeze slobbering
that slobberingdie slobbering
our slobberingonze slobbering
your slobberingjouw slobbering
every slobberingelke slobbering
which slobbering?welke slobbering?
a big slobbering / the big slobberingeen grote slobbering, de grote slobbering