Model Sara and mechanic Callum from Edinburgh have been hooking up for a while and now think they're ready to get serious. But Sara is concerned about Callum's flirtatious reputation with the ladies, and it seems her lack of trust is justified as Callum has also been seeing her best mate Ruth. Unaware of this, Ruth is hoping to make Callum her own. Meanwhile, Sara's friend Craig is struggling with his turbulent on-off relationship with boyfriend Sam. It's Craig's party and he's decided Sam's not invited, but that's not going to stop Sam turning up! As the party kicks off, so does the gang... Will they manage to resolve their issues, and who will leave with whom?