cheesy 和 tacky 和 flashy 的差別在哪裡？如果不好說明，請提供一些例句。

Cheesy describes something that is inauthentic or unpleasant to the point where it's almost funny. "His grin was desperate and cheesy."

Tacky describes something showing poor taste or quality; it's a word someone might use to describe something they think is ugly when they don't want to outright offend the person who owns that thing. "It's a little bit of a tacky sweater."

Flashy describes something that is so gaudy and showy it seems unpleasant or in poor taste. "He buys flashy cars for the self-esteem boost."