When is it canonically said that Karkat has a matesprite? Not arguing against it, the Strider Talk made things pretty clear. I just don't recall that being said.

Jasprose says here that Karkat is in a matespritship with someone on the meteor and Vriska says here that Karkat was very cagey about his romantic affairs. Also there’s this vine of Hussie confirming davekat. And before anyone jumps on my ass about “oh jasprosesprite was made with pre-retcon rose so she couldn’t have known about it” Jasprose says here that she recalls the lives of many Rose’s.