Sorry but reddit is delusional. A person in crime ridden South Africa sending a picture of his ding dong to a teenager in a far away land will not ever warrant an interpol response. Depending on how young you were, cultural differences, and age of consent laws, there’s likely not even a theoretical possibility to go after him for it even if it’s just socially and not legally, if this is all you have any credible proof that he’s done, that is.

If you want to frankly waste your time on getting revenge, your best bet is the normal legal grey zone harassments posted here all the time unless you want to risk getting into trouble. But this will probably be more of a nuisance for you to do than for him to be the target of, since, you know, he’s in SA.