MacObserver:

If you are currently an Apple TV+ and CBS All Access (CBSAA) subscriber, you can get SHOWTIME free. Your subscription status will automatically reflect the new bundle. However, there’s a slight trick involved.

Read the post for the details, one of those things that’s good to know, even if it doesn’t apply to you, on the off chance you know someone it’d help.

From the fine print:

With Apple TV+, add SHOWTIME to CBS All Access at no cost. Without Apple TV+, it’s $20.98/mo.

That’s a pretty penny. Check out the Showtime web site to see what they have to offer.