User blog comment:SayuriDarling/The House of Hades Official Discussion/@comment-5390473-20140222210344/@comment-3146930-20140222224621

That is actually what most people dislike about the book. I mean most people accept the fact that he is gay and even Rick himself flat out confirmed it on his Twitter (I think because Nico admitted to having a crush on Percy, but that by itself doesn't mean he is gay). However it really comes out of nowhere; as Nico somewhat hero-worshipped Percy for a long time in the books, but it didn't seem like Nico liked him that way. He even blushed around Juniper in TLO. However the only build up we get is a small comment in MoA that Annabeth thought Nico had a crush on her and then in HoH, it is just like "BAM! I'm gay." I mean it really just sort of happened. I personally would have seen Nico liking Bianca that way as more believable, as he has been looking for her for most of the time after she died.