Having anal sex with a girl placing your hands on her hips and slowly raising them to head height in the shape of antlers impersonating a moose with out her seeing what you are doing.

when you're hungover as shit after a spending a night drunk as a skunk

Sex with members of staff lower than yourself, while at work

The act of inserting both thumbs in the anus with fingers stretched out giving the ass "Moose antlers"