I dont feel bad for him at all. I feel bad for the girlfriend, she says she is fine with nao having sex with other people. Alright she is cool but from my point of view, she is a crazy woman. Why are u allowing ur boyfriend to have sex with other people moreover in front of u. I feel like that's not real love. If u truly love someone than u want that person to desire only u. There is no f way I would allow my boyfriend to have sex another person other than me. But I guess her way of love is different. I find nao the most creepiest char in this manga. He says he loves her girlfriend the most but just because ur girlfriend is fine with u having sex with other people that doesn't mean you would continue to do so. If you truly love only her than desire only her. Sorry for my ranting, I just dont like nao and his girlfriend mindset.
Uhh there as lots of people who love and are in relationships that are "open". I don't think sex is the foundation to a good relationship. "Love" and "Desire" doesn't necessarily have to go hand in hand. Nao and his gf are in a consenting relationship, i think you're just projecting your idea of a relationship onto them. While it's ok cuz this is a story and it's fiction, i hope u don't say it to ppl irl.
Somehow I feel bad for nao because ryo always does it with chika but at the same time idc :(