It seems like the Groom will always notice you even though you are stealthed, he calls the guards downstairs and they will thus always chase you.
As I'm not near the quest yet, I watched a tutorial.
3, find Vittoria Vici.
Plautis Carvain and his wife can be found traveling in the wilderness, and claim to be heading towards the wedding, although they never appear and are not mentioned afterwards.
roulette casino game rules
If you crouch down behind the couple you will not be seen by them or the guests.