Lust and infatuation are two similar terms that present unreal states of sexual desire or love. While lust refers to a state or an act of having a sexual desire toward another, infatuation can be said to be a state of folly, when one is being infatuated into a system or passion (especially love) in such a way that the person is not really acting in his or her real senses. Though lust is mostly used for sexual desires, it can also be used to refer to some other things that seem materialistic.
For example, Lust after money, which means one strong appetite for money. Lust for power means a state whereby someone has a strong appetite for power. Lust can be considered as a sin, this is because it involves illegal, fatal, or even ungodly things to achieve its passion. Infatuation, on the other hand, refers to a short term attraction towards something or someone due to a particular agent of attraction like appearance, walk, expression and many more.