The reality star, 30, revealed she had joined the 'mile high club' during a game of spin the bottle this week.
The racy confession was aired in Saturday night's Unseen Bits which shows funny moments from the week that don't always fit into the main episodes.
In the game Ekin-Su raised her hand when the group was asked if they'd ever joined the mile high club.
She said: 'I had sex on a plane... with a stranger!'
Her fellow Islander Ronnie Vint then joked: 'He was the pilot.'
But Ekin-Su then replied as she clarified the situation: 'He wasn't the pilot... it was in the loo.'
She looked embarrassed as Casey O'Gorman quipped: 'Ekin loo?' - leaving the whole villa in stitches.
It comes after Love Island fans were left fuming and branded Elma Pazar 'childish' following her heated row with Curtis Pritchard over Ekin-Su on Friday's instalment.
The TOWIE star, 32, snapped during an explosive argument with the dancer, 28, after Ekin-Su kissed Sammy Roots - who is Elma's love interest inside the villa.
Big Brother star Ekin-Su stamped a smooch on Sammy's lips during the infamous Heart Rate Challenge, although some fans were quick to point out she 'barely kissed' the former winner, 23.
Taking to the fire pit with Curtis after the Snog, Marry, Pie challenge - he didn't hesitate to remark Ekin-su was 'quite upset' to see Elma's reaction, saying: 'You come across as very hot-headed sometimes.
Yet she quickly replied stiffly: 'I don't think I do.'
Fans of the ITV show flooded X, saying Elma's attitude was 'childish' for her age and called her out for her 'rudeness'.
Posts included: 'Elma is sooo childish. And she used to be one of my faves #LoveIsland';
'Oh no Elma is very in the wrong here and now she's doubling down, this is not a good look for her #LoveIsland';
'Nah elma is so rude i need her out of the villa asap idk how she got fav girl tf #loveisland';
'Ekin barely kissed sammy. Elma can bore off #LoveIsland';
'Wtf I'm not usually shocked at this season but Elma shocked me there that was so rude #LoveIslandAllStars';
'Ekin barely kissed sammy. Elma can bore off #LoveIsland, adding: This favourite girl vote has gotten to her head. When did Elma get so rude'.
'elma is one of those girls that can't take accountability for anything she does or how she makes people feel, the way she talks to everyone is disgusting and then she walks off ??? #LoveIsland'.
Love Island: All Stars continues on Sunday at 9pm on ITV2 and ITVX.
LOVE ISLAND: ALL STARS LINE UP
GABBY ALLEN
AGE: 32
SERIES 3 LOVE ISLAND
Why do you want to return to Love Island?
Because it's the trenches out there! I feel like I have all my ducks in a row, it has been 8 years since I went into the Villa. I now run my businesses and I've grown up a lot… but I just haven't found 'the one' yet.
KAZ CROSSLEY
AGE: 29
SERIES 5 LOVE ISLAND
Why do you want to return to Love Island?
The first experience I had was so amazing and also so much fun! I'm even more mature now so I'm ready to find a relationship.
SCOTT THOMAS
AGE: 36
SERIES 2 LOVE ISLAND
Why do you want to return to Love Island?
I've been on a massive journey over the last five years; I've been working on sobriety, personal growth, self development, when I first went into the Villa I was still a bit of a boy.
RONNIE VINT
AGE: 28
SERIES 11 LOVE ISLAND
Why do you want to return to Love Island?
I learnt so much from my experience last time. In the Villa I was always in 'triangles' and what not, but I feel like I've grown up a lot.
LUCA BISH
AGE: 25
SERIES 8 LOVE ISLAND
Why do you want to return to Love Island?
I had such a good time last time, why not? I get to have a good time with the possibility of ending up with someone.
CASEY O'GORMAN
AGE: 28
SERIES 9 LOVE ISLAND AND LOVE ISLAND ALL STARS SERIES 1
Why do you want to return to Love Island?
Getting to go in within the first few days of the show, I feel like I've got such a big opportunity to find someone and hopefully come out of the Villa potentially with a girlfriend.
TINA STINNES
AGE: 29
SERIES 2 LOVE ISLAND
Why do you want to return to Love Island?
It was the best experience that I've ever had, it made me learn about myself and grow.
MONTEL MCKENZIE
AGE: 27
SERIES 10 LOVE ISLAND
Why did you want to return to Love Island?
I want to find love and Love Island is the best environment to find that.
CURTIS PRITCHARD
AGE: 28
SERIES 5 LOVE ISLAND
Why do you want to return to Love Island?
I feel like I'm in a different stage in my life. The idea of settling down is a serious idea in my life right now. I haven't found my true love.
NAS MAJEED
AGE: 28
SERIES 6 LOVE ISLAND
Why do you want to return to Love Island?
It was so much fun the first time around, waking up every day with a smile on my face - it feels like a full circle moment.
CATHERINE AGBAJE
AGE: 24
SERIES 10 LOVE ISLAND
Why do you want to return to Love Island?
I want to find love again, I want to give it another shot because it works!
ELMA PAZAR
AGE: 32
SERIES 5 LOVE ISLAND
Why do you want to return to Love Island?
I want to have fun and I want to give it a proper go this time. My time was cut short the first time round and who knows, I could be the next Sophie (Piper) and Josh (Ritchie) or Molly (Smith) and Tom (Clare).
Ekin-Su Cülcüloğlu
AGE: 30
SERIES 8 LOVE ISLAND
Why do you want to return to Love Island?
I want to return to Love Island again because it's where my journey started and has a special place in my heart. It's somewhere I've laughed, cried and learnt so much. The fact that there's an opportunity to do it again - why not!
GRACE JACKSON
AGE: 26
SERIES 11 LOVE ISLAND
Why do you want to return to Love Island?
I feel like at this time in my life I'm in a very settled place. I know who I am and I'm at the age where I've had enough of my single years. I've done everything I wanted to do in my single life and I'm looking to settle down and create a nice life with someone. What better place to do it than in the Villa?
RON HALL
AGE: 27
SERIES 9 LOVE ISLAND
Why do you want to return to Love Island?
I know it works from last time, I was a success story from it, I found love. Obviously it didn't last, but, if it can happen again, great.
HARRIETT BLACKMORE
AGE: 24
SERIES 11 LOVE ISLAND
Why did you want to return to Love Island?
I think that my last time in the Villa was cut too short so I think I deserve a second chance, I'm looking forward to it!
