Param is NOT in a relationship with Hwi. They're going on a date, yes, but they're not currently dating. I don't get the Param hate either. I'm team Hwi, and it will obviously suck to see Param fucking another person; however, they're not exclusive, so they can have sex with whoever they want.
Y’all are exaggerating. Param’s not just going to shake off the feelings he had FIRST for Han.