And it came moments after Aubrey O'Day predicted it would happen.
"Lewis is wound so tight," she said, "Jesus, he's going to snap one day and it's not to be pretty. He's wound so f**king tight."
Moments later that snap came as Heavy continually interrupted Lewis and Marnie as they spoke in the smoking area.
"Oh leave it," Lewis complained at first.
Marnie added: "All you do is speak and we're all f**king tired of hearing it."
But Heavy continued, eventually resulting in Lewis squaring up to Heavy.
"Mate just s**t the f**k up, just shut up for two seconds, shut up, I'm trying to talk to her and you're winding me up," he said with clenched fists as Marnie tried to drag him away.
"Woah, easy tiger, you're rude," replied Heavy D.
In the aftermath, some of the other housemates put the blame for the whole thing on Bear.
Frankie Grande told Marnie: "Heavy is Bear's puppet and he's like a wind up toy, that's what I've always been saying.
"Bear winds up Heavy and lets him do chaos and doesn't care which direction it's fired at."
Celebrity Big Brother airs tonight at 9PM on Channel 5.