Confusion jokes

A man comes home and finds his wife in bed with another guy. "What's going on here!?" he exclaims.

The wife replies, "See, I told you he was stupid."

How do you confuse a ginger?

Throw a cross at them.

Is sex a joke? Because I don't get it.

How many Alzheimer's patients does it take to screw in a lightbulb?

To get to the other side!