I'd go visit Grandpa by yourself...and to minimize the cane surprise, you could decorate it with red and white to make it look like a candy cane, and tell your Gpa that you wanted to look Christmassy
It is a rude awakening when our parents jump down off of the pedestal we put them on to show us that they are flawed humans just like the rest of the adults. When they begin to scar our souls, I feel it's time to cut them off. If you're embarrassing him so,
you'll do him a favor by not showing up in his life. He'll be the loser in this.
In a way, it's a good thing that you'd had the cloud of depression lift before he hit you with this...you must have been stronger emotionally to be able to deal with his ignorance of how what he'd say would affect you. And shame on your step mom...just goes to show it takes all kinds to make a world
Take care of YOURSELF...