call and tell him saves both of you time,if you tell him in person thats jus akward cus he is definitely tryna bang you.
Just don't go on dates with him while he still thinks he's dating you. I mean, you might think you're just hanging out, but to him it's a date. Make sure he knows it's not a date, then see if he wants to hang out with you or not. Otherwise, you're just leading him on. In fact most girls do that, they decide they like a guy, but are not attracted to him, yet they don't tell the guy they're not attracted to him, so he still thinks he might have a chance and after a while he's like wtf and you're like wtf I thought you knew...
Wtf, you do NOT arrange a second date to break off ties with someone.. If a girl did that to me I would be mortified. Call/text his ass. Because as soon as you mention you aren't interested he will not want to be around you lol.
lead him on for a week then tell him on his birthday that you have a boyfriend, sorry for giving you the wrong impression yeah, that didn't happen to me or nothin...