"I Can't Stop Now" was featured in the Season One episode. "Tom's Rhinoplasty".
Background
Wendy Testaburger becomes heartbroken, due to Stan Marsh ignoring her in favor of Ms. Ellen.
Lyrics
I remember when we were so in love
The moments that we shared were timeless.
Saw it in the wind, knew it in a glance,
the songs we sang were simple and rhymeless.
I can't stop now
My heart's awake
I feel your arms
My arms to take
I must have changed.
Even when love is the same.