Big Sean issued a warning in a now deleted Twitter post to Justin Bieber to "not touch" his girlfriend after the pop star hugged his Ariana Grande following a live duet.
The rapper was unhappy with the embrace the pop pair shared during and after performing the sensual song 'Love Me Harder' - which Ariana originally recorded with The Weeknd - at a concert at the Forum in Inglewood, Los Angeles, on Wednesday night (08.04.15).
During the duet, Ariana even broke into fits of giggles as Justin draped his arms over her shoulders and Big Sean took to Twitter to express his anger.
In one deleted tweet, he simply wrote: "Wow."
While in another, now erased, post he warned: "This kid is about to learn not to touch my girl like that. Beliebe it. (sic)"
Justin and Ariana also sang 'As Long As You Love Me' together at the concert, part of her 'The Honeymoon Tour'.
Ariana, 21, and Big Sean, 27, have been dating for over a year and are said to be in a "serious" relationship, but that didn't deter fans from taking to social media to declare Justin, 21, and Ariana looked "cute together" and should "get together".
Another fan posted online: "I just can't get over Ariana Grande and Justin Bieber. I mean yes Ariana and Justin have a really good chemistry on stage but what we all have to respect Sean and Ari's relationship."
Justin Bieber inspired by Selena Gomez
Justin Bieber's new album will be inspired by Selena Gomez, with the star revealing he is writing tracks about the "happiness (and) heartbreak" of their relationship.
The 'Baby' hitmaker - who split from his on/off girlfriend for good late last year - has revealed he is using their relationship as inspiration for his latest album.
He said: "A lot of my inspiration comes from her. It was a long relationship and a relationship that created heartbreak and created happiness and a lot of different emotions that I wanted to write about, so there's a lot of that on this album."
The 21-year-old star - whose previous studio albums have all reached number one on the US' Billboard chart - is working hard on creating music that documents his journey over the past few years rather than writing the tracks he knows people want him to make.
Speaking on 'On Air with Ryan Seacrest', he said: "There is a lot of stuff that I've been going through over the last few years.
"I just really want to bleed it on this record. I want people to know that I'm not playing around. I'm not doing a record that is cookie cutter or doing something that I think people want to hear ...
"I've been pretty silent about what I've been going through and just growing up in this life is hard, so I want to translate that."