[Marlow]

I have no default here. It strongly depends on the opponent. If someone has been doing this to me 2 or 3 times in the last few orbits, then I'll 3/4 - full pot it just to see what happens.

You also need to examine how often you make continuation bets. He might realize that you are way out of line, and has found a cheap way to punish you.

If you have not been making too many of these, then you need to make a statement. You can't let a playewr think that he can mess with you, or it won't ever end. Push back with nothing or push back with something, or check-raise, or do something that scares him.

Most of the time, you want to fold in this situation, tho.