>>1
First, do you know him? If no, then back away. Bringing something like that up to a stranger/semi-stranger is always a bad idea.
So, let's assume you know the person you're thinking about. Are you aquaintences from school/work, or is he already a friend? It's easier if they're already your friend than if you just "know them".
Are you already in a relationship? Is he? If you answer yes to either one of these, then do not pass go, do not collect $200.
So, if thus far all indicators are Green, you know and trust him and he's a friend, you're both single, etc., then you're ready to go onto the next step.
How do YOU feel about sex without love? Are you the type who thinks sex should only be shared with someone you love, or are you the type who sees sex as more a psychological/biological need? What about him? do religious beliefs play any part in either of your decisions? If you did have sex with him, would either of you feel gulty about it afterwards? Do you both feel you can have sex without loving one another?
These aer hard enough questions to ask yourself, let alone someone else. There is an easy way though.
First, examine yourself. If you have sex with him, could it be "just sex"? No guilt, no worry, just two people having fun in one of the oldest ways possible? If you can answer yes to that, then go to the second step.
Second, buy condoms. Don't assume the guy has a few boxes at home. The LAST thing you want is finding out in the heat of the moment that he came unprepared.
Third, time it. If he's a good friend, then he won't think twice about being asked to hang out with you at your place, or inviting yourself over to his place, or meeting up someone on neutral ground. Just relax, have a bit of fun. Talk nonconsequentional topics. If you know each other from work, bring up something about your supervisor/manager. Gently lead the questions a little more personal (if you start here right away, he's gonna start getting odd vibes--it's all in manipulation). You know, something like "If you could change three things about yourself...", or "If you could have sex with one movie star...". Do NOT bring up marriage, children, where he sees himself in the future, etc!! Once he's comfortable talking abuot personal stuff, ask him right up, "How do you feel about the whole 'friends with benefits' thing?"
If you created a comfortable atmosphere then his antanea will go up, but he'll also answer honestly. If he says he's not into the whole idea, then back off. If he says he isn't sure, then proceed cautiously. Try to coax more information out of him if you can, because this could swing either direction, and just asking him "do you wanna find out?" could potentially kill whatever relationship you already have with him. If he answers he's into the idea, then push it.
Remember though: You are coming on to him. Do NOT expect he'll pick-up on your signals and understand right away what you're trying to do.
Most importantly though is this: Be safe and have FUN.