BLACKENING

A 'blackening' - a Scottish ritual of mess-making.
A bride and groom, each separately, get 'tarred' by their best friends a few days before the wedding.  Treacle, coffee powder and flour are used for the tarring.*
The whole group are driven around town in the back of a pick-up for a couple of hours, occasionally leaving the victim tied up to a lamp-post for a while en-route.  Drink is imbibed throughout.
[*Orkney council forbids blackening clean-ups in public toilets.]
 And there is a lot of squealing, shouting, banging of improvised drums and continual tooting on the van's horn.

The tradition might well have derived from a gentler old routine where a bride's friends would wash her feet before her wedding, in later years the friends would blacken the feet first to make the washing worthwhile.

[Husband's photo from the doorstep, the group are at a local slipway used by swimmers.]