Connected to a blog I no longer own via JetPack

Hi,

So here’s my situation.

My old domain expired and someone bought it. I’m still connected to that blog with my WordPress account because I used Jetpack when I owned it.

Yesterday, a tweet was posted on my account to a 404 page on that site for some reason. I looked at what app was used and it said “WordPress.com”.

How can I disconnect?
(Sorry if I’m posting in the wrong forum. The WordPress.com forums are full of spam, ignorance and rudeness.)