We’ve all heard that age is just a number, but that doesn’t seem to be the case when it comes to a significant age gap in a relationship, as one such couple found out. After being slammed for their 42-year age difference, the pair responded to their critics. Do they have a point, or are their naysayers right? You decide. Keisha Louise, 18, and her 60-year-old boyfriend, Dimitrios Fotis. (Photo Credit: Screenshot) Keisha Louise, an 18-year-old so…