Show me the person who says they didn't tear up at this and I'll show you a liar.
The fact that Skip got his shades forever ago from Rittz as a christmas present, and never stopped wearing them. When they broke, Rittz got him new ones, while not as cool he wore them anyway.
The same comic also reveals that the team name Mek Pen (short for Mechinal Penguin, and revealed in the characters bios to have been thought up by Rittz) was named after a stuffed robot penguin Skip got Rittz in return.
In the most recent comic, Skip's "date" offers him a cigarette, which he declines with "A friend of mine's mom..." before cutting himself off. It's implied Skip doesn't smoke because Rittz's mom died of some form of lung cancer.