Let me answer your question as you presented it, for it solicits a qualified answer:

a. If the offended spouse is the husband having discovered his wife having an "affair" with the girl, then he should look himself naked at the mirror and blame his worthless war machine;

b. If the offended spouse is the wife having discovered her husband having an "affair" with the girl, then she should do a "Bobitt" and stuck that worthless piece into his throat.

Seriously,extra-marital affairs are not new anymore, it has been here since time immemorial, long before marriage was given sanctity under Family Laws. Even American presidents do it for sheer stupidity. Offended spouses took calculated steps depending on the gravity of the offense and the possible social effects that the scandal will bring if brought to light in public.

Filipinos are highly religious people, but their extraneous acts betray their loyalty to their religion. Appeal to carnal knowledge and extra-marital affairs are a constant embassment committed by people both obscure and the famous, news on graft and corruption far outplace worthy articles on front pages, and these all happen because society cant care more than what is to cook for supper.

I have handled annulment cases in my trial practice in the Philippines and the end losers are innocent children having had to suffer from thier parents' misbehavior. The thin fiver of society, our children, who will carry whatever legacy we leave, are forever damaged because of our indiscretion.

Talk to you husband in a manner like you are just getting married, set aside your anger, and convince him that the interest of your marriage and your children's future are of paramount interest than the temporary scent of that other woman.