Was Jack jealous of Dirk during Dirk's first scene with Amber?

Not sure what you saw in that first sex scene, but what I saw was Jack looking happy that he found another "star" to keep his enterprise afloat. Jack pursued Eddie at the Disco because he seemed to have grown tired of his current batch of performers who all exhibited interests outside of porn movies. Jack wanted a young gun to step in and take it up a notch.

I thought he was just very impressed with the performance and probably didn't expect it from a total rookie.