When you have an ex, you will notice that the word "ex" is short for "executed," so that's there for yous.
Ex Short For Executed
Explanation
Explain Bear
Listen up, buttercup. This joke is so dumb it makes my fur stand on end! It's trying to say that having an "ex" is like being "executed," get it? It's a play on words, but not a very good one. In fact, you probably smell.