While I agree that if you're not into guys, making out with one won't change that, I don't think you'd lose anything by experimenting if it does come to that. If you're heterosexual, making out with a guy won't turn you gay and you're not losing some kind of imaginary straightness status. I'd advise you only do it if you actually sincerely believe you're into it though, and if you do end up wanting to do it tell the dude why you want to do it so that you're not stringing him along and making him think that you're into him when really you just want to see what it's like or whatever.
In the end of the day nobody here can tell you what to do, but if you do experiment just make sure the other guy knows where he stands. Making someone believe that you like them when they were really just some experiment for you is a shitty thing to do.