I wrote about this before but it keeps getting funnier.
Max has discovered that his farts make us laugh. Not so much the fart but the face he makes when one trumpets out his tiny cheeks. So now anytime he lets one go, he waits for us to laugh, and then, after showing how pleased he is with himself, he tries to squeeze out as many more as he can. When he's all red-faced & can't get anymore out, he tries to mimic the sound with his voice. Such the comedian.