Why Won't Her Boyfriend Cut Off His Toxic, Violent, Vodka-Bottle-Swinging Ex?

Savage Love Letter of the Dayby Dan SavageLong-time reader, first time writer here.
I’m a 26-year-old bi woman dating a 36-year-old man for about ten months now. The relationship itself has been amazing. He’s an incredibly sweet, caring, and affectionate guy who goes out of his way to make me feel appreciated. Not to mention, he’s super fun to hang out with! And the sex is fantastic!
There’s just one problem. He’s still friends with his ex-girlfriend. They were toge