The spelling of the word "extracurricular sexes" can be tricky due to the combination of two words with different pronunciations. The first part "extra-" is pronounced as /ˈɛkstrə/ while the second part "-curricular" is pronounced as /kəˈrɪkjʊlər/. Similarly, the word "sexes" has a distinct pronunciation of /ˈsɛksɪz/. Therefore, the correct spelling of the term would be /ɛkstrəˈkʌrɪkjʊlər ˈsɛksɪz/ which should be pronounced with stress on the second syllable of "curricular".