James , in a fit of laughter slapped Artie 's back , and for some reason , this caused Artie 's head to randomly explode . James stopped laughing and turned to look when his horse suddenly reached up , with its neck stretching to accommodate its actions , and bit off James ' head . Both human bodies then fell off their horses , only to sink like bricks in quicksand in a pile of horse manure .
Question: What stopped James 's laughing fit ?
The answer to the above question:


He made his part of his friend blow up .