What do you do about a cheating spouse who will not admit they are cheating?

suerone asked:

If someone is cheating on you and you have all the evidence from their smell, to their body language etc. plus the fact that you know the person so well you know they cheated.
Do you:
a) Confront them
b) Strategically get yourself together and leave without their knowledge.
c) Ignore the situation in hopes that it will change.
d) Other
Exlpain please