What does it mean if you dream of kissing a guy you are not even sure if you like him or not?

Most relationships are initially based on some kind of attraction, namely physical. Now if you've known this person for a fair bit of time then comfort is a factor. You feel safe with your friends, and if you're single and don't want to be its easy to be pulled toward your friends because you already know them. Or it could be that the only reason you don't "like" him is because you keep telling yourself you don't for one reason or another, when in reality you probably do. We are generally hard wired to seek out those of the opposite sex we are attracted to in some way, usually what makes them just friends is an extenuating circumstance or two. But honestly you're probably just feeling a small bit of pent up attraction, you can let it pass or let it out.