In Leeds, 19-year-old Jack has been enjoying the sexual benefits of an open relationship, but perhaps a little too much. In Exeter, Kev has been told that one of his exes might have given him chlamydia, Tilly's worried about a potential unplanned pregnancy and free spirit Chantelle can't see why the risk of STIs should stop her experimenting sexually.

In Leeds, 23-year-old Krista and 20-year-old Emma have come to the clinic after enjoying the benefits of recently becoming single, while Geoff is facing the prospect of a third bout of chlamydia. In Exeter, Josh has had chlamydia before, but has he learnt from past mistakes? Ash worries that he could have passed on an STI to new boyfriend Jazz.

In Leeds, 18-year-old ladies man Ollie has been enjoying himself, mostly without protection. 20-year-old Heather has been suffering with genital warts. In Exeter, farmer Greg is suffering with pain down below and his new girlfriend won't sleep with him until staff have got to the bottom of it

In Exeter, 21-year-old Scott has been partying so hard he can't remember who he's slept with. And will it be double STI trouble for brothers Robbie and Tom after a season of festival fun? In Leeds, 25-year-old Chloe is facing the prospect of her second STI, while ex-army recruit Carl has heard rumours that an ex may have given him chlamydia.

Best friends Eve and Joel are worried that ex-partners may have left them with more than just memories and decide to come to the clinic to find out for sure. Likely lad Tony wants to overcome his fear of getting tested to find out if never using a condom has left him with an STI.