Lassiter is not pleased when he is roped into keeping Shawn Spencer in his custody overnight. (Shawn/Lassiter first time/possible relationship.)

Shawn and Lassiter are shocked when versions of themselves from a parallel universe come through the mirrors and are stuck in their world; more shocking still is that their alternate selves are in a serious relationship. The alternate Shawn and Lassiter jump into the investigation, aided somewhat awkwardly by the original Shawn and Lassiter. (Shawn/Lassiter established/developing.)

Shawn and Juliet have an open relationship and are quite happy together...until they run into someone they used to know that they've both always been interested in. They all spend the night together, but it's soon clear that they all want more. (Shawn/Juliet/Lassiter OT3 series PART ONE.)

While trying to protect Shawn from a vampire attack, Lassiter is forced to ingest vampire blood; fortunately, Sam may have read about a possible cure. Also, Dean is outed by his dead father (which wasn't news), and Juliet is a BAMF (also not news). [Shawn/Lassiter and Dean/Cas at the end].

The world is ending, sure, but something else could be starting. In which there is absolutely no more pie, and Shawn needs to take off at least one sock for common courtesy. (Shawn/Lassiter Zombie Apocalypse one-shot.)