Have you heard of “mentionitis”? It’s when someone constantly talks about another person they are obviously infatuated with. It could be “work wife” or gym buddy, or new friend, and it’s a sign that someone has definitely caught their eye. For a single person, it’s cute and sweet (though maybe slightly annoying for others to have to constantly hear about this person). But if a partner has mentionitis, relationship experts say it's a red flag and sign of potential cheating … whether physical or emotional.