The spelling of the word "hadst sexual relations" may seem confusing at first glance, but it is actually quite straightforward once you understand the phonetics of it. "Hadst" is pronounced "hædst," with the "a" sound being a short "a" as in "cat." When pronounced together with "sexual relations," it creates the phrase "hædst seksyuəl rileɪʃənz." This archaic form of "had" is a second-person singular past tense form used in Shakespearean English to mean "you had."