This only started last week. Whenever my cat is sitting down, he has his right-front paw raised slightly as if he is trying to keep it off the ground. I have felt The whole leg and compared it to his Left one and all seems normal. He is not crying or anything, he is just being his usual annoying self.

Is there any reason behind this odd posture?

As cat owner, I would be to check if my cat is injured.
Most cats try to avoid showing signs of injury out of instinct.

If it keeps up for a a couple of days, take it to the vet. Normal sores would heal by then.

Have you checked all the paw pads for thorns or stickers?