WanderingAway, I think I understand where you are coming from. Not me personally as I am not the OW, however, my DH left his ex because she was having an affair with OM. OM has always behaved like some macho-I'm-so-loved-up-with-your-ex, and-we're-together-and-you-are-not arse. He always ALWAYS has to be present if DH is doing drop-off or pick-up with his ex. They always have to hold hands. Yet whenever I or anyone else does the drop-off or pick-ups he is never there at all. He never fails to call DSS 'son' in DH's earshot. It's been 5 years, and he's still point-scoring.
My DSS gets tagged in their gushy statuses on FB, and because they do this the statuses appear on our newsfeed. OMG you have never read such drivel. It's all a show, and doesn't bother us one bit, but it just looks pathetic and tbh if I was DSS in about 2 years time I'd want to defriend them so that my friends don't get to read it!
We are married with 2 children, and I think it sunk in this year with the ex that DH really has no interest in her life. All the, 'look our lives are better than yours' stealth boasts that get inserted into texts/emails about DSS are just ignored and have slowly dried up.
Personally I think if you've gone to the trouble of splitting up someone's marriage, and then make the children see one parent EOW you really have to show the world that it was worth it. Plus there must always be that fear that the person you won as a prize in the competition with the married partner, may just run off with the next convenient person to escape with from the drudgery of normal life. I suppose as your partner was once married to the ex partner, they were clearly once in love and attracted to each other, the ex must be the biggest threat? That's my theory anyway.