Once upon a time, a lovely girl in her early 20s met a man at a party in his mid/late 20s and they hit it off. They exchanged numbers, went on a few dates, and over all enjoyed each other's company.
BUT THEN! The evil summer arrived and split the blossoming romance in twain, the girl had to journey back to the north while the man languished in the damn DC heat. They called each other and texted, but still the distance was too great, until fall returned and the girl made the trip back down to DC and rejoiced to be with her highly attractive friends ;) once again.
After making plans to hang out with the girl, the boy flaked. They made more plans, and the boy flaked.
Finally the girl was like, 'yo what's the deal,' and the boy said, 'sorry i've been real busy with work and the girl that I'm involved with.'
The girl was shocked, as was I when I heard the tale, but the question is... what to do?!
Well I don't suggest bashing the windows of their car in (or do I?).
But you do have a few very important things to decide right there and then.
1. Ask him if he's serious/exclusive with the other girl. If he is, then you have some options.
A. Continue seeing him, damn the other girl, he's fine and you want him now... and tomorrow... and the day after that. (This is also know as being the "other woman." If you are prepared for this highly contentious title, go ahead, but I can guarantee the emotional stress will take a toll on your life and strain your relationships with those around you.)
B. Stop seeing him.
C. Be his friend, if you're the bigger person. You could also just lay and wait till he dumps the other chick and swoop in when he's emotionally fragile.
2. Let him go.
3. If he isn't serious/exclusive with the other girl, he might just be keeping his options open. In today's society it's not unknown for people to date 3 or 4 girls/guys at a time, because you never know which one is greater. Also known as, unless there's a rock, it's not official.
For this option you should be glad to know that he is still interested in seeing you, however, you should also be prepared to take certain precautions for intimacy, because if he's doing you, he's probably doing her, and you don't know her... so you don't know what she has...
All in all it's a complicated situation in which you need to talk to the other person involved and decide for yourself, where to go from here.