But don’t let him break promises.
It’s one thing for your man to say from the beginning that he’s not in but what about the guy who says he’s “gonna go” and then bails at the last minute? That’s just plain bad manners. If you’re habitually responding to Evites with one “yes” and one “maybe,” you know you’ve got a guy you just can’t count on. And if you can’t count on him for minor things, what other promises will he break?

See the signs.
We’ve dated enough guys to know that they all have their flaws, but being unreliable may not be one you can put up with. “Keep an eye out for guys who consistently offer lame excuses for missing events from the very beginning,” says Cohen. You may decide that if he’s not going to show up, he’d better ship out.

If he’s committed to you, he should keep his commitments—even if the event is long, dull and there’s not a beer in sight. Besides, how dull can it be if you’re there?