Inasmuch as it makes some people uncomfortable, I don't think there's anything wrong with it.
Once you've dumped your boyfriend/girldriend/fiance/fiancee it's none of your business who chooses to fall in love with him or her.
And they never asked me how I would feel about it or thought about how it would effect me.
I cannot imagine my brother going out with my ex-girlfriend! so I will not do it to someone else, and if worse comes to worse and I have fallen in love with the sister of my ex and she feels the same way then i must date in secret becuase I know there is no way my ex will be happy about it!
I, like the Debugger(one of the forumists) Would only support Seun's view if the case of the rejection of a lover by the other is considered strictly though I will not do it no matter the case.
At some point, my ex and I have had feelings for each other, shared special moments together and all...of a sudden I'm trying to experience the same thing with my ex's sister?
In the event that it does happen, I know the relationship with my ex's sister won't lead to anything serious.babadudu: No, I can't date my ex-lover's sister.
As for the brother in law, if he falls in love with his brother's ex wife years after, this will only lead to a new relationship.