The Shag is a bird.
It's normal for blokes to shag birds.
Sometimes blokes shag blokes,
or birds shag birds, that's okay too.
Shags even shag Shags
but neither blokes nor birds shag Shags - it's frowned upon.
You may, however, bird the Shag.
That is all.
(Inspired by a post form Relax Max)