pick up after (someone or oneself)
To collect and put away a mess that someone or oneself has left around. You really need to pick up after yourself if you're going to use my workshop. I'm so sick of picking up after the kids. They need to start putting their toys away at night!
pick up after someone or something
to tidy up after someone or a group. I refuse to pick up after you all the time. I refuse to pick up after your rowdy friends.