The term "mertua menantu selingkuh" appears to be related to family relationships and potentially infidelity. "Mertua" typically refers to the mother-in-law, while "menantu" refers to the son-in-law or daughter-in-law. "Selingkuh" is an Indonesian term that means "affair" or "infidelity". "Jav" could be an abbreviation for "Japanese Adult Video" or a similar context.