Gabby and Natalie came to blows in the bathroom after Natalie claimed Gabby was excluding her and Rodrigo from her workouts.
Gabby denied the claims, insisting: "I don't feel like I'm excluding you, it's a free for all."
But Natalie accused: "You're only telling the boys when you're working out."
Gabby hit back: "To be honest Natalie you aren't really that approachable anyway you made me feel uncomfortable a couple of times yesterday."
Natalie reacted: "Don't think just because I'm only the American black girl I can't shout because you're shouting louder than I am. Don't start because you have not seen me get loud."
The row then escalated as the girls began to argue about who had shouted first.
"Don't start. You've not seen me get loud," Natalie concluded.
Following the row, Gabby was left in tears in the Diary Room asking to go home.
The pair's latest row follows Natalie kicking off on Monday.
Natalie was keen to know what 'storm' surrounded the other housemates, but they weren't all that keen to share.
Natalie continued: "Why is it so f**king tense? Is your storm that bad? Then I really want to know
"I would like to know who you guys are, I'm living with you, I'm sleeping with you guys, I'm showering with you guys. I would like to know and I'm going to ask."
Natalie's questioning left some housemates uncomfortable, with Gabby in tears.
"It's the way everything's said. Being put on the spot stresses me out," Gabby told Dan Osborne.
He replied: "That's just the way she is. That's her character, that's the way she speaks."