A little about me so you can make a better descision: I am a VIRGIN and am very mature and definitely not the type to fuck around. So just casually fucking him is NOT AN OPTION.
Most Helpful Guy
Seriously, Fuck Boy? You do realize that his friend may (Mostly he is) be lying bout how many girls he talking to. And I'm not asking because I know he didn't fuck all those girls. The fact that his friend had to tell you probably means he ain't a fuck boy (Most likely an imitation)
Anyways if you wanna date him, it's no different for any other type of guys (So right now I just have to assume you haven't dated anyone before). You have to be interesting, have a skill, be fun to be around, have a talent or something to differentiate you from any other girl he could be fucking with (I can bet he be fucking his palm). And you have to attract him without seeming to try. If it sounds too hard just be sexy or cute and act like you ain't very interested in him. (Nobody likes clingy people or any who needy)
For actually dating him, everything I said up there is simply to attract him. Just treat him like you would a regular guy. I mean why did you ask this question? You realize you're infatuated with this guy right? He's likely not gonna change.
You're better off with a Real Man (Like me of course, I could give you vitamin BBC) if you don't know what's an Alpha Male then Google it or something.