Why do people play around with your feelings? Do you ever do it to others?

ppl are selfish and attention seeking at times, and also mean and out for themselves also or maybe they like playing with ppls head, its not necessary or nice. Yes like u said, it is a recipe for getting walked on if u arent like this, sometimes, I dont care! im not going to pretend that im interested when im not. In the past I have played with feelings(not anymore) I have also had my feelings played with. whats wrong with being upfront? ppl just cant and wont be honest at times.