Turns out baby Groot wasn't just trolling Drax when he wouldn't let him see him dancing. According to director James Gunn,
There was actually a scene that we cut from the movie where big Groot was dancing to 'Livin' Thing' by ELO. And it wasn't such an elaborate dance. It was more that he was just moving up and down like this, and Drax was dismissive and gave him this look like he was a loser when he did that.Dancing is ludicrous to Drax. I don't think he understands it. If Drax owned a town, if he was a mayor, the first law would be no dancing. But yeah, so at the end of the movie, little baby Groot didn't want to get caught dancing, because he would kill him.
The more you know. I say dance on little buddy, you've got moves!