FRIENDS go out to coffee TOO! Here’s the beauty of asking him if he wants to grab a cup of coffee:
1) As you guys are standing around talking, if you get the feeling that he is enjoying the conversation and wants to keep talking, you can just say, hey, what are you doing right now? Wanna get a cup of tea/coffee over at (wherever is near, starbucks or whatever). THEN, if he really doesn’t want to, he can say, oh I can’t right now… but he’ll give you an IN if he wants to do it some other time. Generally he’ll say, oh, I can’t right now, but let’s do that some other time, or something like that.
2) If you don’t want coffee on a sunday night, and you’d rather do it some other time, or if you just want to give him the IDEA, you can – in a spirit of friendship – just keep a little pad of paper and a pen in your purse (is if it were ALWAYS there) and while talking just say, hey, we should get a cup of coffee sometime.. and as you’re saying it, take out your pad (so you don’t even have to look at him when you say it (and write down your number and tear it out and give it to him – COOL AS A CUCUMBER. And you can add, give me a call if you’re bored this week. I always like making a new friend… or something to that effect.
3) HE WON’T BE ABLE TO TELL FOR SURE whether you are INTERESTED in him. I mean, think about it, maybe you’re just friendly and comfortable with people and it’s no big deal! How would he know? So it’s not like he’ll think, oh hell, she wants me, now what? and have to start avoiding you. In all likelihood, you’ll have coffee and either enjoy it or not enjoy it, and then go from there. Then it’s in his ballpark. NOTHING SERIOUS. Just coffee!

In conclusion, I believe I have proved here that YOU HAVE NOTHING TO LOSE. go for it :)