While driving in the car:
Michael: After farting, "Man, I have had really bad gas lately."
Me: "Do you fart like that at work?"
Michael: "Yes, It's just gas, actually more like air."
James: listening intently, "Daddy, maybe it's Magnesium"

I freaking love this kid!!! I mean Magnesium really??? He's so funny!
P.S. Courtesy of James, i love aliens 5 years old