They overlap, producing a bond. So in this case, when this Lewis acid interacts with this Lewis base, this one S interacts with this two p.
These two electrons are donated to this two P orbital. Now, as these come closer, this load becomes smaller, this becomes larger so that the overlap is better. And we form SP three hybridized bonds. So 1234 SP three hybridized bonds. And now this carbon and this H share a pair of electrons.