If you found out you were an OW, would you tell the 'other woman'?

[Undertone]

Long story - but the gist is that the man and i were in a full blown relationship for 6 months but he called it off after i told him i loved him... to continue his relationship with a long distance girlfriend he'd been with for 6 years. They had lived together at the beginning for a while before she went back to the Philippines. While he and i were together they spoke every day etc. But i had no idea. She wants to come and live with him next year in the UK - leaving behind family, friends, job, pets - everything. He told me that she doesn't know about me and 'couldn't handle' knowing as she was so 'emotionally immature'. That pissed me right orf.

Is it ever acceptable to warn another woman, especially when there's so much at stake, about the man she'd be throwing her lot in with?

I would want to know if I were her. Perhaps a short mail at first " Hi, my name is X. I have had a relationship with your boyfriend from x date to y date. I did not know about you until he broke it off. If you would like to know more about this, please contact me at... email address..." ( don't make her a Facebook friend .. she might stalk you). that way, she has been informed without the gory details and she feels like she still has some choice in the matter, not that it's all been forced upon her. They might also have agreed that they could have an open relationship when apart .. which sucks for you.....