[Lex]

It's about time that the rest of the viewers that think Mark is just some kind of funny and genuine character in the house...and believe that he belongs in the final 5 realised that he is a true game-playing snake that would be only too happy to throw 'anyone' under the bus to get where he wants to get!
He is no one's friend in the house, because he is incapable of seeing anyone as more than a competitor for his crown!...but will readily affect a slow-burn showmance with Christopher for the purposes of gaining air-time!!
...And to cut a long post short, his entire game-plan is to appear to be a nice but slightly camp-eccentric that would never 'play a game' to win!
...And as to him trying to protect "his friend Christopher" by not telling him that the two new house-mates are "snakes in the grass that can't be trusted"...well how does that "protect" Christopher, when not knowing this vital information might lead him to fatally misjudge their true character at a vital moment?? ....Yep!, and saint-Mark knows it as well!! ...nasty boy that Mark!