The two stars, as well as their fellow housemates, were handcuffed together on Friday evening's launch (3 January) before entering the CBB house, as part of an entertaining new twist on the reality TV show.
And it has't taken long for them to get properly acquainted!
Despite Lee previously admitting that he finds housemate Jasmine Waltz attractive, it now looks like he also has a thing for the brunette Essex model on his arm - or should that be wrist?!
Yesterday (5 January), Casey and Lee got closer than ever before while lying in bed and, after endless flirting and numerous cuddles, the pair were caught having a rather steamy kiss.
Pop singer Lee initiated the smooch by passionately grabbing Casey's face.
Lee was then seen going back for another kiss and showering Casey with pecks on the cheek until she told him to stop.
However, the Blue boy band member appeared to be undeterred and was heard telling his new crush: "All you need is some loving".
Before the bedroom lights went out, the twosome were seen chatting to fellow contestant Jim Davidson about going on holiday to Dubai together.
Jim then added: "Life's too short, enjoy yourself".
Could his words of wisdom have spurred Lee and Casey on?!
Viewers can watch the kiss on tonight's episode of Celebrity Big Brother on Channel 5.
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