I have a very close female friend who suggested she pretend to be pregnant with my child/children.
Also, the ex was always jealous of said friend and this is why I'm thinking of going with it.
campaigner act I know, but sometimes you just have to do these campaigner things!
Hang on, you think that advising the ex that you will involve the police if the harassment continues is inflammatory, yet you are thinking of going with this idea?
That is a tactic I would strongly advise against if she is a crazy as you say.