I headcanon that Kris and Berdly actually go way back as friends, likely since kindergarten (or the equivalent), and they were always pretty close to each other, maybe not as close as Kris was to Noelle but they were definitely friends who hung out quite a bit and enjoyed their time gaming together (whether this relationship was entirely platonic is uncertain)
Then all of a sudden Dess goes missing and within the span of a few weeks, Kris shuts down and ends up in the worst depression of their life and just avoids social interaction for years, slowly drifting away from all their friends who don't know what's happening and want to reach out to ask what's going on but can't, and on the other hand the spelling bee incident happens and Berdly is forced to become the smart kid, something that over time through his own expectations on himself and doubts becomes his smartass persona and his extreme self-esteem issues
Eventually the two began to interact again... a little, but at this point it's been so long and it just feels awkward and irony poisoned, and while they wouldn't admit it to anyone they both miss what their relationship used to look like, they miss when life was simple and all they had to think about was getting to hang out with each other and with Noelle and staying up late playing Super Smashing Fighters, they miss their weekly sleepovers and getting to cuddle, they miss those days but it's too late now, and as their insecurities eat them alive they wonder if they could ever reconnect, only to put that thought down as they convince themselves they'll never feel the same way again