The pair, who previously were 'a thing' on the outside, lock lips as the housemates play a game of truth or dare.
Their kiss follows Isabelle "selflessly" putting herself up for eviction in a new twist.
On tonight's show, the housemates take part in the next part of The Hunt, they each have a save button that they can press, only once, in secret to save one housemate but they cannot save themselves.
When all buttons have been pressed, anyone not saved will be targeted and at risk of facing the public vote.
Isabelle and Sam are not saved by any of their fellow housemates, but only one of them will be put up for the public vote. Sam and Isabelle must decide between themselves which of them will face eviction this week and Isabelle volunteers.
Housemates watch on from the Living Room and criticise Sam for not trying to fight Isabelle in her offer of being targeted. It becomes a talking point for the housemates who have respect for Isabelle’s “selfless” act.
Meanwhile, elsewhere in the game of truth or dare, Raph is dared by Chanelle to give her a lapdance, to big cheers from the rest of the housemates while Simone is dared to give Sue a sexy lapdance.
Hannah then plays a prank on the housemates in Rose Cottage by knocking on the window while they’re in bed, causing them to all scream.
Later on, Andrew and Raph talk in the garden about Andrew struggling in the house. Andrew admits to Raph that he fancies him and they agree to remain friends.
Big Brother 2017 airs tonight at 10PM on Channel 5.