Dylan receives his Chlamydia diagnosis and has to contact all the girls he has ever slept with to inform them. He casts his mind back three years ago to Abigail, the first girl on his alphabetical list of exes, who he met at a wedding. A flashback reveals a defining moment he'd previously tried to forget.

In a flashback to 18 months ago, Luke is enjoying the best sex of his life with psychology student Cleo, but he's trying to avoid deep conversation in case she finds out how shallow he really is. When Dylan gets dragged along on their date he takes a shine to mature student Anna. To Luke's dismay, Dylan invites the girls over for a proper dinner party where he hopes to impress.

In a flashback to 10 months earlier, Luke drags Dylan and Evie to a posh party in the countryside. Luke is desperate to sleep with childhood crush Ilona McLeod, who holds a prominent position on his 'things to do before I die' list. Meanwhile, a bored Dylan and Evie amuse themselves by attempting some of the unchecked items on Luke's bucket list, with disastrous and unexpected results.

Flash back to 3 years ago. It’s Evie’s birthday and she is planning on telling Dylan she has feelings for him, over a quiet meal. But her plans are de-railed by a surprise, culminating in a busy night at A&E due to a sexual mishap. And back in the present day, Dylan reconnects with Abigail.

In a flashback to four years ago, Dylan has been seeing Bethany for several months, but she’s been leaving an awful lot of ‘products’ in his room. When she invites her protective big brother over to dinner a terrifying thought occurs to him - has he fallen into a serious relationship accidentally? Meanwhile, Luke drags Evie to a work bowling night in order to find out why his new boss Diana has turned all the women in the office against him.

Enthusiastically encouraged by Luke, Dylan sets about tracking down a girl who hasn’t returned any of his messages: Phoebe. But when the two of them show up to larger-than-life Phoebe’s family home, they receive some unexpected news from her mother. Also, in a rare reflective mood, Luke pressures Dylan to finally tell Evie he loves her. The question is, will Dylan bottle it?