To upload this thread and asked this question has always been on my mind but for some strange reason I have been reluctant about it until I saw the thread by Andrew on the topic of How Would You React If You Know Your Dad Is Cheating Of your Mum?,  so I thought instead of degrading the thread by raising my own question I should upload the original one that was intended being how would you react if your brother or sister in-law is cheating on sister or brother.

I love my sisters a lot and although they are not yet married I something wonder what will be my reaction if they get married and their spouse begin to cheat on them cos I have no intention of cheating on my wife.

I am really concern cos my friends whose sisters are married seem to see nothing wrong with their brother in-law cheating on the sisters. The other day I was with this friend of mind in a hotel (pls don’t ask me what I went to a hotel to do cos am yet to be married and I went for casual drink up) when his brother in-law came out of one of the room with a girl (trust me she is not his business partner even my friend knows that, they must have gone to “knack” he told me) without any remorse he walked up to us and ask the bartender to fill our table and to my greatest surprise my friend was totally calm and happy about it.  He later laughed and talked about it as though it was normal.

This act kept me wondering. Was he trying to protect his sister’s marriage by not saying anything (there and ever) or did he consider it normal for men to cheat on their wives? This and many more I couldn’t figure out so I decided to bring the matter to nairaland.

What would you have done?

Drink wit him n den talk

@poster
the guy in your story gets his "silence" paid for in beers, thats how cheap the guy is (selling his own flesh and blood for drinks).
it doesnt matter why/how/what or when it happens, the guy has a DUTY to tell his sister of his suspicions.
the important question everyone should ask themselves IS: if your friend/sis or bro saw YOUR partner coming out of a hotel with some stranger, would you want them to tell inform you?!

no matter the consequences, you have to clean your conscience right away by either confronting the cheating person and asking them to change their ways OR informing your blood.

¶ thought ¶ wil be on ma own on dis as ¶ suspect many other nairalanders wil be cool wit it. The truth is dat cos U̶̲̥̅̊ r †ђξ man in †ђξ marriage is nt a yardstick to cheat on ur wife.
Also again ¶ wouldn't want ma sister to divorce him cos ¶ don't want dis tag od divorcee on ma sister, ¶ want her to hav a hapi family n mother all ma niece n nephew for †ђξ same man. Therefore ¶ tink if it was M̶̲̥̅Ƹ ¶ wil confront my inlaw

confrontation the in-law and after that tell your sister and after that collect money from the man to help facilitate settlement.
Or better still blackmail the man right away!!