As they sit there laughing and talking...they may be cold-hearted and feel no shame, but believe me this does not escape the eyes of the crowd around you. I know I had sons who were young and in sports and my ex and his young girlfriend always made a show, but they are the blind fools...people don't always come up to you and say they understand and know what fools they are, or sometime's they do, (I have had a few who have) but believe me they see what is happening, they know. I had someone tell me once that once my divorce was final and over, people will come out of the woodwork and tell you what they have seen. This was true also. Even now I run into someone who may say something. Your husband and this woman can live in their own little dream world and believe that just because people aren't coming up to them and saying things, that all is well and good, but truth is always there no matter how quietly it sits. Just ignore them and take the high road. Grace and class go a long way and you know they don't have any for what they do.
PS: I live in a small town and things always get around. I'm sure my ex is out doing damage control. No amount of sugar can change something, it only covers it for so long.