Yeah ... I think he's being too stubborn. And if he wants to deny / resist his feelings then stop kissing Kirara! You jerk
He's such an hypocrite
I bet his brother is already with one
hm I think Ken staying with his dad is proof that he agrees with what his brother said for the both of them to a certain degree and I am sure they discussed it, they are siblings after all. He blames his father for ruining their mum's life, for falling for a man and wants to be a burden for him - that's not very supportive. It'd explain why he is being a hypocrite.
I do understand why you feel that way and I guess we'll have to wait and see anyway... for me, I think he could very easily be angry at his dad without it being for homophobic reasons. Maybe he feels that his dad was dishonest or treated his mum badly by marrying her, having kids, then leaving her to go back to guys... I'm basing this on him saying that he's not going to be like his "shitty old man." And that may not be the true situation with his dad! But Ken might see it that way. He doesn't necessarily agree with his big brother about everything, even if they're siblings.
I just can't really see him as homophobic, since he has been initiating stuff with Kirara quite 'comfortably,' stopped everything with girls when Kirara criticised him for it (and maybe because Kirara got hurt because of it), and seemed angry and frustrated that Kirara dismissed his big move (the first kiss) from the beginning as revenge/teasing/joking and said it didn't faze him - ie. didn't mean anything to him.
I may be wrong! Although so far we've only seen him avoiding Tarou-san, possibly keeping his bro away, if he's ever actually nasty to or about him or about his dad for being gay then I will humbly eat my words. Like I said, we'll probably have to wait and see when/if we get Ken's perspective. He's not very expressive and kinda hard to read, actually ( ̄∇ ̄")
Ken better come into terms with himself, apologize to his dad, confess to Kirara and suck it up already. His wannabe 'insecure and homophobic' ass definintely likes him and leans that way. So just do it ~(๑•ㅂ•)و✧