How do I turn off the iPhone Lock Screen preview of 'Now Playing'?

While listening to music, podcasts, audiobooks etc I do not want them to be shown on my lock screen. How do I turn off the lock screen preview of Now Playing? I have kids and don't want them to be able to see what I am listening to if I lock my phone. It seems the only way to do that is to turn off whatever I am listening to. I have it on my watch and use that but don't want it on my actual phone.

[Re-Titled by Moderator]

Original Title: how to NOT show what I am listening to on my lock screen