I'm pretty sure that the 'blonde' they're referring to is Cleveland.
In Asia, dyeing your hair blonde or other stranger color usually means you're a delinquent, party people, chad. So in the NTR trope it's usually a dyed-hair dude that steals the normie protagonist's girl. And that kind of person is now simply referred as "blonde". ....Well yes, in this specific comic it's referring Cleveland.
Sucks for Cleve, cant even get a dance with her gf
Start Building!Episode 65: The Thwarted Love MK.II
Nice, change your pose!Pro...protect?No worries, we are fully prepared!Extremely IntenseUm, thank you for helping me prepare my clothes...ゴゴゴゴゴゴゴBut where are yours?Good! Look here!We will protect you!ゴゴゴゴゴゴゴStay away, blond
"Blond" is referring to Cleveland.