Love Island: All Stars couple Gabby Allen and Casey O'Gorman's relationship seems to be at risk of petering out after the couple had a major argument. The islanders took on the Heart Rate Challenge tonight, with the performances starting right at the beginning of the show. By the end, however, plenty of drama was created as the boys and girls tried to raise each other's heart rates with racy dances. After the challenge, the results were read out revealing who'd managed to raise who's heart rate the most.

Despite giving their own partner special attention, Casey and Gabby didn't match up. Gabby's heart rate was raised the most by Curtis Pritchard, while Grace Jackson caused a major spike in Casey. Speaking as a couple after the results were spoken out loud in front of the whole group, Gabby admitted that they weren't sitting well with her. "What is wrong?" Casey asked, with Gabby responding: "I just think it's a bit muggy, that's all." After Casey confirmed Gabby was talking about him, she added: "I just like, we've been Hideaway and everything together, and like, it didn't go up for me. Obviously I'm going to be a bit miffed.".

Casey asked: "Is that in my control?" Gabby stated: "Well you obviously weren't turned on by me." Casey then let out a huge sigh and covered his face with his hands, saying: "Oh my God, we're not doing this. Gabs, we're not. That's like me getting at you for getting it raised by Curtis.". Gabby then explained why she was so upset - and it was about Ekin-Su in particular rather than if any of the other girls had got Casey going. "I think just because out of everyone, she's the only person you showed any sort of interest in when she first came in, that's all," she said.

The duo didn't seem to get anywhere in their chat, with Gabby later saying: "I'm allowed to be a little bit miffed by it." Casey seemed to have given up completely, exclaiming: "Okay, be p***ed off then!" Gabby responded: "I'm not p***ed off anymore! But we're having a conversation about it. That just didn't feel nice, that's all. I know there's nothing in it." Earlier in the episode, Gabby revealed she felt "mugged off" after the revelation that Grace caused his heart to race.

"Also 'cause I f***ing slept with him as well, so embarrassing," she fumed. Despite saying she was sure it meant nothing, the duo's argument didn't seem resolved as Gabby refused to feel Casey's heartbeat as he told her it was high now. "Casey literally has 0 emotional intelligence. If it was the other way round he would be complaining big," one fan weighed in on X, formerly known as Twitter. Alongside worrying Gabby by raising Casey's heart rate with her moves, Ekin-Su was accused of betraying Elma Pazar after she kissed Sammy Root, despite promising not to. Ekin's own partner Curtis also admitted he was "gutted" by her wandering lips.