DP's sister is obsessed with his ex GF. They have kids together & DP's sister dislikes the ex, but still manages to keep track of ex's life & feed this back to DP. DP is very good at telling his sister that he's not interested & that it's all irrelevant to his life. But I'm getting pretty fed up with hearing about it. DP's sister & I get along fine, we're not best friends, we haven't swapped numbers etc but we're friendly enough to each other. It's really quite bizarre. Anyone else have this?