My two cents worth: you should tell him that your son is seeing a counselor for the depression. If he then wants to know more, then that will be up to you: allow him to talk to son himself, or tell your H to come along to a session with you.
ME:51 W:46 M:25 S:22, S:20 Divorced 16/9/15 BD 10/12 W left 12/12 with OW, affair confirmed Nov/12. Dark since 6/13 I"m in a new relationship since Feb 14.
