Sometimes my coworker will give me attention and I'll secretly enjoy it.
What does he do that is inappropriate?
He stares at me often. I suspect he likes me.
Even if you don't mind your coworker staring at you, he is creating an awkward working environment. You should always feel safe and comfortable at work, and not harassed.
It's alright, I might be using him for my plans.
What kind of plans? Why would you want to use someone like that? You should instead tell him to stop staring at you, because that is very inappropriate for a workplace.