I think he actually believes all his own excuses.

Lee means exactly the opposite of everything he says, so to understand him you need to bear this in mind! i.e
"I don't want a relationship!"
"I'm not a player!"
"I've never lead Casey on!"

And his message to Jasmine "I never led Casey on ... An' I don't want you to think that as soon as you left I jumped straight back onto Casey's boat because I didn't... I've not led Casey along to think we are anything else but just friends" when everyone in the house was telling him just this and it's recorded by 24/7 CCTV. What an idiot.