>You can’t exactly stand up and walk out of a wedding mid-ceremony, so I just had to commit to this act and spent the next 20 minutes awkwardly sitting there trying to be as inconspicuous as my 6ft 2 ass could be

And yet, no one actually seemed to notice him other than the photographer (who presumably didn't know most of the guests beforehand), and the bride and groom only found out he was there because the photographer took a number of pictures with him.

Once the ceremony starts, you stay quiet. Getting up and leaving from aisle seat while the wedding party is coming down the aisle would have been a jerk move.