give (one) a hard time
1. To tease someone about something, often for one's own enjoyment. I hate talking to Uncle Ned at family parties—he always gives me a hard time about being a poetry major. I'm pretty sure that Kevin likes Katie, so I keep giving him a hard time about it.
2. To treat someone harshly and make things difficult for him or her. I think I've done a good job at work, but the boss keeps giving me a hard time—I don't think he likes me very much. Stop giving the interns such a hard time! They're doing the best they can.