And if you stay after 90 days without a visa, what does it threaten?
You overstay your time. You basically “spoil” your visa as some would say.... next time you try to use it Immigration will basically deny you entry and cancel your visa. Hope this Explaination helps.
To say you “basically spoil” your visa is an understatement... as soon as you overstay your visa it gets automatically voided and cancelled. And then the chances of ever getting another one are basically zero.