Taking Adam down a peg in full view of the other Islanders, Rosie gave her partner the opportunity to come clean, but when he claimed not to know what she was "on about", she took matters into her own hands.
ITV have also revealed they "have no current plans" for Niall to appear on spin-off show Aftersun with Caroline Flack.
Now The Sun is reporting that he left because of health reasons.
'Duty of care is the most important consideration on shows like this and as soon as he felt unwell, ITV would have had a discussion with him about leaving.
"The decision they took would have been taken between all parties with Niall's health being the only consideration".More news: Pruitt asked security detail to take him in search of lotion
The islanders were told of his exit in last night's episode.
His departure will be seen on tonight's episode with Alex George telling fellow islanders: "For personal reasons unfortunately he can't continue or come back to the Villa".
"Absolutely gutted Kendall has left Love Island but I am the proudest sister in the world". We got on really, really well.
Taken aback by his sudden departure, Dr Alex admitted Niall will be missed by all as he reiterated how much of a "great guy" he is.
She told him: "You say about Niall not being honest the other night, but you literally did what he did. and didn't have the balls to tell me before that you were going to do it".More news: Google will ban inline extensions starting with Chrome 71
'He was actually my friend, my buddy'.
A single Niall then coupled with newcomer Georgia after a sizzling first date.
"Let's go for the one who looks like a prostitute because I'll get my dick wet faster". And just being happy and bubbly.
This week it will be up to the girls to decide who they would like to couple up with.More news: Robert De Niro Stuns Tonys After Saying 'F*** Trump' - Twice
Love Island airs on ITV2 at 9pm on weekdays and Sundays.