The daughter of former Magpies man Michael Owen, Gemma Owen, is currently on the popular dating show.
Gemma has kept her dad's identity under wraps thus far in the villa, but it is no secret to viewers at home.
Funnyman Stirling has prodded fun at the famous Love Islander's father a number of times on the show, but trod a little too close to home on Monday night.
He said: "Luca's grabbed Gemma for a catch up. Gemma was telling me today that she once joined a pony club.
"Coincidently her dad Michael once joined a pony club...it's called Newcastle United."
The comment rattled Newcastle fans, who were quick to take to social media and share their thoughts.
One said: "@IainDoesJokes crossed the line with that Newcastle United joke on #LoveIsland ya haggis eating kilt wearing m**g…"
Another wrote: "Eff off @IainDoesJokes ya pr**k! Lol!
"Don’t call #nufc when Owen was the proper d***heed when at Newcastle.
"Proper rubbish joke mate! At least try and do what you’ve got in your Twitter name."
Someone else shared: "@IainDoesJokes I had a lot of respect for you until that Newcastle comment #LoveIsland."
Others branded the joke as a "low blow" and "Newcastle slander".
Gemma Owen has fast become the star of this year's Love Island series, with producers giving her large chunks of air-time.
Recently Gemma's ex-boyfriend Jacques O'Neill entered the Villa to add some extra drama.
Michael Owen has been outspoken about seeing the negative messages directed to his daughter online.
Speaking to the Daily Mail, he said: "It's hard because I have three other kids and this is their sister and they are reading this stuff.
"[My wife] has been very upset about it. You can say, 'Don't read it', but that's very difficult.
"I know she's been used to that sort of thing with me – I've had it all my life.
"To look at my social media feeds you'd think 70% of the world hates me, but it's different when it's your daughter."