Cameron Kasky, an organizer of the pro-gun control March for Our Lives movement, tweeted Monday night that he won’t debate Kashuv, a pro-Second Amendment voice, following a tweet Kashuv seemingly disapproved of.

“Kyle, I’ve enjoyed my discussion about gun laws with you so far, but after seeing this, I think I’m out. For personal reasons,” Kasky said, adding that while he “disagree[s] on certain policies with some family members of some victims,” he would “never go after them, especially not like this. This is low.”