Isn't it more of a rival? Where did you get male interest from?
He's been supportive of Youngguk in the past life even if past!guk had a caustic temper (assuming that wasn't all a bluff and he was actually a meanie who plotted 'guk's downfall).
This is the first time I think where guk has a noteable same-age group male character who's fixated on him (hence male interest).
And with the words he spoke in the last panel, it's either:
a. he followed guk into his regression
b. he genuinely wants to collab with guk and knows nothing about him aside from his fame
c. he's jealous of guk's history and plans to do a yandere on him (๑•ㅂ•)و✧
I hope it ain't as deep as a or c, and is just b.
Kyaa >w<