He will probably throw a tantrum because we didn't believe his story.
stuff, he was already throwing the tantrum by the time I finished my post. Damn. You'll just have to trust me guys, I knew ahead of time. The pathological liars always get angry when called out or proven wrong.
They get a dopamine surge from the manipulation - like the socialization reward section of their brain is broken and they get a nice feeling of belonging when they trick people into feeling sympathy or admiration for them. They anticipate that reward hit and when you take it away they instantly get cranky and it's very hard for them to hide.
You're not going to see an advanced Machiavellian ruse from this guy because it's an impulsive addiction, not an effort to actually cynically manipulate people. He probably hasn't thought the lie through at all.