Rachael, I wouldn't have him served at work. Since he is still living under the same roof, I would have him served at home or you could advise him that you have filed and here is your copy. It's your call, but I wouldn't do it to him on the job.
As for is mother, I would meet w/her and see what she wants to talk about. If she raises the issue of your marriage, you can be honest w/her and tell her it's just not working out and tell her, but don't go into all of the details because it's none of her businss. Yes, he should be the one to tell her, but he's not going to be honest w/her either.
My xh told everyone that we had separated, but he did he tell them he was having an affair? No, he said we had agreed to separate because we had grown apart. If someone asked me about the situation, I would say very nicely, that he was the one that "grew apart: when he brought a third party into our marriage. They knew then that he was feeding them a line of BS. So, I wouldn't hold my breath that he will be honest w/her or tell her about it.
Think before you speak when you are talking w/her. I don't know what type of relationship she has w/her son, but you have to be careful because she may be on a fishing expedition to see what you are planning to do. Whatever you do, do not share any information that you have received from your lawyer...blood is thicker than water and no matter what he's doing, right or wrong, she'll stand beside her baby boy.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
