"Sexfid" is a non-existent word, and therefore it cannot be explained through the International Phonetic Alphabet (IPA). However, if it were a real word, its spelling would be determined based on the phonemes it contains. The IPA would be useful in this scenario as it would allow for the clear representation of each sound. The spelling might also lead to variations due to regional differences and various accents. Therefore, it is important to consider phonetics when spelling any word.