As for the FB...Not to burst your boundary bubble, however there are ways to "hide" friends...My H did it with the OW...Verify before bringing it up.
Not to beat this point to death, but I agree the unfriending means nothing if not coupled with transparency. My W unfriendd and blocked OM...then they exchanged FB passwords so they could see everything and of course created new email accounts...
M39 W41 Two children WAW bomb dropped 11/7/09 Piecing Aug 10 - Nov 10 No longer piecing...Nov 10 Separation Jan 11 EA ends again Feb 11 Piecing attempt #2, Mar 11