Is Jackson unaware that his mother wants to jack him off?

She is so transparently sexual with him. The scene where she pulls off her son's shirt and squeals at the sight of his muscular torso is the most slap worthy. And he just goes along with it, like it's not the least bit ODD...

I thought Martha would most want to make Jackson reach climax via the hand job, because of the degree of control it would give her.