Probably someone who didn't want the divorce in the first place? ....wonder why they broke up though (〜￣△￣)〜
well it's not ex-wife but my brother's ex girlfriend (they almost got married) still talks to me and my family, she's really nice
I think in your case, your brother's ex is just really a kind person. But Dojun's ex wife doesn't seem like your brother's ex at all (I'm just thinking this because Dojun's ex didn't greet Heesoo & Hyesung when he saw them even though it's the norm for Asians).
Probably someone who's still in good terms with the family. When I broke up with my ex, his mom called me occasionally to know how I was doing, and my current boyfriend's family has told me plenty of times that should we ever break up, they'd still want to be in my life.
What ex wife still comes over to his ex husbands house like its no big deal and hug the mother?!