This paper examines the Arabic origins of sex and its derivatives like sexually, sect, dissection and formally similar but semantically different words like six, sick, sack, sake as well as reversed forms like kiss, case, cozy in English, German, French, Latin, Greek, and Sanskrit from a consonantal radical or lexical root theory perspective. More precisely, the data consists of three different sets of 30 words altogether, 11 of which are sex derivatives like sexual, sexually, sexuality, sect, section, dissection, insect, 13 formally similar but semantically different words like six, sick, sack, sake, suck, seek, beseech, soak, size, and 6 reversed forms like kiss, case, cozy, cuss. The results clearly show that all such related words have true Arabic cognates, with the same or similar forms and meanings whose different forms, however, are all found to be due to natural and plausible causes and different courses of linguistic change. Furthermore, they show the failings of English and European historical lexicography and linguistics in manifesting the close genetic relationships between Arabic and such languages. As a consequence, the results indicate, contrary to Comparative Method and Family-Tree Model claims, that Arabic, English, and all the so-called Indo-European languages belong to the same language, let alone the same family. In fact, they are real dialects of Arabic. Therefore, they prove the adequacy of the consonantal radical theory in relating Indo-European languages to Arabic as their origin all because, unlike any other language in the group, it shares cognates with all of them in addition to its huge linguistic repertoire phonetically, phonologically, morphologically, syntactically, and semantically.