I just wrote another comment about this. Supposedly Jason didn't feel it with Heidi (Susan) and so the relationship was discontinued at some point. I'd say this

I just wrote another comment about this. Supposedly Jason didn't feel it with Heidi (Susan) and so the relationship was discontinued at some point. I'd say this specifically might be why the relationship worked so well on screen. Sometimes what a project like a sitcom or a business needs is rather someone or several members who don't fit in. Because otherwise you start to suffer from creative and intellectual incest.