It's impossible that any of the housemates are acting. They've been in there for weeks, they would not be able to keep it up. There are plenty of people around, like Jonny and Kate, who are natural "perfomers" and do show off and mess around, but we can't forget that we've also seen another side of them when they can be upset, angry or having a laugh with everyone.
Those of you who say they're false and playing up to the cameras: there are many people who are like that in real life with no cameras around. It's just their personality. It's up to you whether you like people like that or not, of course, but I don't think you can accuse them of being "false".
Those of you who say they're false and playing up to the cameras: there are many people who are like that in real life with no cameras around. It's just their personality. It's up to you whether you like people like that or not, of course, but I don't think you can accuse them of being "false".