The co-stars, who have split up but remain friends, apparently filmed themselves romping while they were in Marbella last month.
Lucy’s ex Mario Falcone was seen confronting her in last night’s episode of the hit ITV2 show after hearing the news from his friend Chris Drake.
Clearly fuming, he told Lucy: “You want to talk about disrespectful? Disrespectful is doing a sex tape in Marbella.”
But Lucy, 21, raged: “Disrespectful to who? Even if I did that how is it disrespectful? How many times did you cheat on me 30, 40?"
She added: "How many times did you sleep with a girl and then come home and get in my bed?"
Mario, 26, tried to defend himself by claiming it was actually "seven girls”, causing Lucy to walk away in floods of tears.
Later in the episode news of the sex tape had spread and Tom Pearce and Arg were seen discussing the gossip at a Michael Jackson themed fancy dress party.
Lucy and Dan, who were both guests at the bash, did little to stop the rumours when they met up for a chat.
The boutique owner, who was wearing a silver gown, recounted the conversation with Mario in the park.
Referring to her ex she said: “Go and enjoy your own sex life, don’t get involved in mine."
Dan responded: “It’s nothing to do with anyone what we did anyway."
Lucy told him: “You’ve treated me with more respect in two weeks than he has in two years."
Dan then revealed he is planning to confront Mario about his meddling.
The couple split up after a few weeks of dating when Dan discovered his ex-girlfriend was 13-weeks pregnant.
The dad-to-be recently opened up about his decision to end the relationship, saying: “I don’t think it would have been fair on either of them if I’d continued to date Lucy. I want to concentrate on one thing at a time.
He added: “It doesn’t necessarily mean it’s over for good. It’s not like we won’t speak again. We still hang out and go for dinner with groups of us.”
