I did this with my first 14 children but they caught on eventually so they might be aware of the plan already. It's still might work, this is PETA we're talking about, but you might have to mix it up a litttle. Like for example, say your son is a hairless dog instead.
I gots say, the meninism part here is kinda sketchy. She's an asshole for doing it, but he's also an asshole for cheating in the first place. Edit: thanks for the inbox explosion. Didn't realize this was counted as revenge porn and was illegal. In that case I can start to see the disparity.