Emotions are irrational by definition
Since emotions are controlled by the limbic system, the prefrontal cortex (our rational brain) never gets involved before an emotional reaction occurs.
It necessarily follows that emotional decisions and emotional thoughts are inherently irrational.
It is important to know that emotions are considered to be irrational, illogical and unreasonable since they are carried out by the limbic system, which is separate from the neocortex, which deals with reasoning, conscious thoughts, and decision making.