My response:
Now that we have the "grounds" under Virginia law, proving the allegations "is a whole other animal".
So, photos, video, tape recordings, can't hurt. It's really difficult to deny the testimony of a videographer or a photographer when he / she testified that you were caught on film "doing the nasty" with someone else; and then, having that proof entered into evidence !
When California had "Fault" divorce laws, film always did the trick. But, alas, we don't have "fault" divorce any longer, so the need for Private Investigators and photographers is "a thing of the past".
IAAL