The broadcasting watchdog has received 650 complaints about Sunday's episode of Love Island, after Dani Dyer was left devastated by a clip of boyfriend Jack Fincham.
The daughter of soap star Danny Dyer burst into tears when she learned that Fincham is in another villa with a former flame.
The complaints related to "distress" caused to Dyer because of the video clip, Ofcom said.
The couple are currently in separate villas, after the boys and girls were split up and new contestants entered.
In Sunday's episode, Dyer, who has been coupled up with Fincham since the start of the series, was shown a clip of the pen salesman reacting with shock as he realised one of the new girls was someone he has previously dated.
She said: "It always happens to me, as soon as I'm happy with someone, something happens to me, it's like I'm not allowed to be happy.
"Imagine it's some girl that he's been recently seeing, he clearly has feelings if he was seeing her and now she's in here.
Speaking through floods of tears in the Beach Hut, she said: "I knew it was too good to be true."
She does not know that Fincham has been sleeping outside to avoid sharing a bed with any of the new contestants.
He has also told Adam Collard that he is in love with Dyer.
Dyer has also remained loyal to Fincham, sleeping on the sofa to avoid sharing a bed and refusing to kiss Dean Overson during a game.
An Ofcom spokeswoman said: "We're assessing these complaints against our broadcasting rules, before deciding whether or not to investigate."