Guys gets WRECKED on social media, so he deletes and HIDES.

A woman's adultery does not reflect on her husband, it reflects on her. She is an evildoer, and so is the man she cheated with. That last part will shock some people. What that does is make prostitutes the best option for sex outside of marriage, as they should be.
Our adultery problem partly stems from our bizarre stigmatization of prostitution in America. Being known to have fucked someone's wife vs being known to frequent prostitutes, I wager the latter will be more socially harmful to me. We jail men for seeing prostitutes but adultery is non-criminal!

To answer his question at the beginning, I disagree with the theft analogy and I don't see this as stealing anything. She has free will, she chose who she wanted. This guy's boast was weak, but it's not like he went Ocean's Eleven and pulled the caper of a lifetime, he just capitalized on her hypergamy and the other guy 'lost out' on someone that was clearly not interested in him anyway. Bullet dodged for one, fair play for the other two.

If anything it only makes alpha-shrimp look weak for trying to throw shade on the other guy for clout, and it makes her look bad because she appears fickle and disloyal.

Who cares... Shit happens move on