Get another girlfriend

Talk to an ex.

Say "You have a boyfriend I have another girlfriend, so? I share you you can share me!" Or something along those lines. Those aren't the best put words.

Tell her to choose (I wouldn't recommend this, but it's an option I guess :S)

Don't talk to her, if she cares about you then she'll come back to you and seek attention. This should probably be tried first.

Deflorated Mistress: STOP SPAMMING!! Aren't there some mods to infract this sorry excuse?