Complex sentence: It first aired on February 11,1998, in the United States on Comedy Central; it is considered the show's first Valentine's Day episode, since it came out three days before Valentine's Day and involved semi-romantic plot-lines.
Split into simpler sentences: It first aired on Comedy Central in the United States on February 11,1998. It is considered the show's first Valentine's Day episode, since it came out three days before Valentine's Day and involved semi-romantic plot-lines.