Muskmelon
Muskmelons can widely vary in taste, depending on each fruit: some are sweet and some more closely resemble their cucurbitaceae cousin, the cucumber, in taste.  In 1513, a Spanish writer said of the muskmelon that "the good [muskmelons] are like good women, and the bad like bad women."  Maybe expecting all melons to be sweet, which is not the case as mentioned earlier.