The one you're thinking of is the touching and very beautiful episode entitled "Rivals In Love"!

If that's not what you're thinking of, you can find out what you've missed right at the end of the white DVD which features Jennifer the Human, who was the very first Human to assume the Embodiment of Love in this or any Surgical Sideshow episode.

The grand debut occurred, not surprisingly
at the Peats Ridge Festival with the rest of the repertoire at the time
of the 29th, 30th and 31st of December, 2006.
The event was the Skellingtons first exposure to Infant Humans in the wild.

The Skellingtons performed this sublimely sensitive episode at the end
of the Bonedaddy Website Launch at Figureight, which happened to be in Alexandria back then. That was on Friday,
the 27th of April, 2007.
In a peak of emotion, the Skellingtons were physically accosted, during the act, by an enthusiastic audience member who just wanted to hug them. Years later, it turned out to be their future Human, Hannah!

Jennifer, however, was fast fading and the Skellingtons saw the immediate necessity to go back to the Graveyard to film this episode for the Future.

The next time you might have seen this episode performed, Irene had joined the Surgical Sideshow for their first great excursion to Katoomba, otherwise known as the Blue Mountains.
The Mela Dolce troupe had invited Irene and the Skellingtons to join Lytex, Milly, Minnie and Venus in a grand performance of many parts
at Tris Elies
on the 22nd of March, 2008. It was quite jolly!

Hannah became the third Human to play the Love Heart, on Saturday,
the 4th of October, 2008, but the first to perform it in broad daylight.
This happened, in the open air, just outside the Hub in Newtown as part of the Under The Blue Moon event.
Ironic, no?

This episode hasn't been performed at any other time.
If you don't remember any of that, you must have seen some other show.