The smile he makes as his car starts in one of his videos.
When he goes to Subway and gets his sub, he points out that the sauce in his sub is spilling out in a pool in his wrapper, so it looks like it's "had a good cum session" to him. He even imitates what he thinks the sub must be feeling. "Ohhhh..."
Him complaining about kids who bash Path of Exile thinking it's a ripoff of Diablo, when it was made by the ex-developers of the latter.
Nick: (as a complaining kid) This game is a ripoff of Diablo. I'm not gonna play it. It's so lame. It's just a ripoff of Diablo. It's made by the people who made Diablo, you stu—
In the "Perth Milks It" video, one guy has his back to the camera and looks an awful lot like he's masturbating, but then he turns around and shows that he was very vigorously and suggestively shaking a milk carton.