What happens if the president wins the popular vote and lost the electoral vote?

The president then is what the name suggests: the president. (it's the electoral vote that counts, not the popular vote).

In fact this was the purpose of the original electoral vote (among others): the conviction than masses can be manipulated and that the electoral college can choose better.

If anything, their opponent gets to feel very, very flustrated.

Lol passover. jewish holiday. hope this !