Going around during Christmas time and taking people's light up deer and putting them in odd, funny sexual positions. The ones with the moving heads are real fun
duuude lets go deer mounting my neighbors just got a herd of them!
Reindeer mounting is commongame played around Christmas time. You and a couple of you buddies go driving through unknown neighborhoods or your own and place stupid light up reindeer on the hinds quarters of the others.
for examples on Reindeer Mounting seesex and doggy style