Looks like they were filming a wedding on the set of Bel Ami.
A twitter friend @Lara82 was at the Bel Ami set observing and tweeting.
Here is a summary of her tweets as of 3am PST (which I believe is about noon in Budapest non?)
Aprox 10:30pm PST (7:30am in Budapest)
Crew setting up lights for interior shots. Wedding set-up looks beautiful. Barocque style, a chandeliere, white flowers (mostly orchids) with green leaves and white bow ties. Lot's of paps.
Aprox 1am PST (10am in Budapest)
Extras in costumes standing outside set waiting and smoking. Holly Grainger is inside wearing a white dress (not a wedding gown though) with a blue shower cap on her head.
Aprox 1:30am PST (10:30am in Budapest)
Rob arrives in black troussers, white golden wedding jacket, bow tie. Smiled quickly at fans and went inside.
As of yet there are no photos or videos but I bet as soon as they wrap for the day they will emerge and I will find and post them :)
Till then - expect some fancy wedding attire on our fave non-vampire soon!
**Links to Everything Bel Ami Here**