Hopefully you recognize Colin in the middle. Sam is to his right and Ben to his left. I know what your thinking but Colin only looks bigger because he is more propped up on the pillow (he and Ben are about the same size, Sam is bigger, at least in weight). Colin is a chart topper for 4 months and the O boys were 8 weeks early so they are still on the small side, they would probably all be considered average 6 months old size. Sam and Ben are very clearly months ahead of Colin (as they should be) in terms of motor skills and cognition. As you can see from one of the 'outtakes' where Colin is still just chillin' (read: stuck) and the O boys have wandered (alright rolled) off.
After we got home, Sean was letting Colin chew on his finger and when he said "Ouch" I just thought he was playing around but he wasn't! Colin is cutting his first tooth. Watch out Sam and Ben, next play date Colin will be biting back! It is his lower left front tooth. Nothing to see yet but you can definitely feel it. He doesn't seem too troubled by it at the moment, we'll see how it goes.