"Sorry," Peter said sheepishly, shrugging slightly. He was glad she hadn't hit him with her telekinesis. That would have been awkward. "I guess I should have known better than to startle you, what with everything that's happening." With Barbas around, it definitely wasn't a good thing to startle Prue, at least not if you didn't want to get tossed into a tree...which Peter definitely didn't want.
"See," Peter said, "I figured you'd say that. But there's one problem with that. You can't actually make me leave. And I'm not letting you do this alone. You're too important to Chris and Piper and Paige. And really? Who else are you going to bring?" He started ticking off points on his hand. "I can't die. I can heal you. I can become intangible so that Barbas can't touch me. I've already dealt with my fears.If, for some reason, you can't get a piece of his skin, I can. And, most importantly, you're family now. And like hell am I letting you risk yourself alone. So, any arguments besides 'no'?"