1. A Green Bow

When Lucy falls in love with a little girl named Fiona that she meets on a call, she wants to foster her, but it would be difficult to get approved as a foster parent as a single woman, so she asks Tim to marry her on paper despite the tension between them after sharing a kiss "for work". Tim agrees for Fiona's sake, but their marriage of convenience quickly gives way to more.

Canon divergent after 4x22