A poem about a 'viper' that one spouse knowingly brings into the marriage.

There is a viper in their house.
It’s managed to stay out of view
after being let loose by the spouse.

Of its dangerous bite, the spouse well knew.
Yet this viper was willingly brought there
without regard for the damage it could do.

Its bite will bring pain, agony, and despair
to the other spouse should the viper strike.
Therefore, guilt and dread pollute their air.

Its venom destroys trust and love alike.
Once the viper is discovered, the same
happiness is impossible as emotions spike.

Be it husband or wife who is to blame,
these mates never forget the viper’s bite.
One must live with anger, the other shame.

Usually their marriage cannot be set right,
with divorce the result. If the union is kept,
resentment and distrust continue the fight.

Does this viper that into their marriage crept
have a name? Adultery! Many tears are wept
over adultery; at ruining lives it is most adept.