Should i get involved when i know another woman is being cheated on?

[ilikeshoes]

My DP brother has been seing this lovely girl (although not officially dating due to his decision they are sleeping together and she has met the family) and i know that he is also seeing other woman although i havent met them, it makes me feel so awkward as i want to tell her as i would want to know if i was in that position but don't want to be classed as the stirring interfering type, as i get on with his family.This weekend we went away as a family and on the last day he invited this girl down to visit she drove 3 hours to visit him and i felt he was just using her as a dial a sh*g for want of a better way of putting it, he had seen other women a couple of days before!! what should i do?

I had'nt really thought of that, do not think i am the best at hiding things especially when i feel strongly about something, i will just try and be really subtle, and not drink too much wine before hand :), as to not let myself just blurt out what that he is seeing other women, we have chated before and she said she wanted to have a relationship with him but he did not want to rush things, but i never thought to bring the subject of not seing other people into it. Fingers crossed i won't come across as a nosy interfering cow, and hopefully she will be aware of the other girls he has been seeing too. thanks for the advice.