Other forms: forbidden fruits
If you're studying for a big test, video games might feel like forbidden fruit. Forbidden fruit is something that is very tempting but that you are trying to avoid.
Something that's not allowed can be especially appealing — that's when it becomes forbidden fruit. Teenagers who are warned not to leave the house after 9 p.m. might consider sneaking out to be forbidden fruit, and little kids are likely to long for the forbidden fruit of the sharp scissors they're not supposed to touch. The expression comes from the Garden of Eden story in the Bible, in which Adam and Eve eat the fruit they've been forbidden by God to taste.