
welp, turns out he's loyal as heck but just full of insecurity after all in the next series.
I don't think having sex and giving BJ to sensei is unacceptable in his case, cause we know Nanao hasn't even together with Aikawa yet, so he belongs to nobody but himself. in another series, we could clearly know that Nanao's been living as if sex isn't something that really matter (even his cousin casually said to him "then let's call uncle and have threesome!", I read it in one of Mujihi series, better check that out) 'as long as it feels good, then let's do it' kind of thing.
I know it kinda sucks for some of us when Nanao 'forced himself' on Aikawa and even Aikawa went along with it. I know at first he just wanted to monopolize Aikawa (like damn he's hot, who can ignore that), but in the end it turned into dersperation for love and to be loved back. If we read another Mujihi series, we knew the main reason he did this because he thought the only thing he could offer for Aikawa to love him was his body (and don't forget there's also rumor about him about having a lewd body to even seduce a man and such. whoops this was revealed in another series, too). And then, Aikawa was straight from the beginning (this was revealed in another Mujihi series), and this added more insecurities for Nanao, so it's actually very clear for me why he did what he did.
And gosh, we actually could know him and his personality deeper when we read another Mujihi series. trust me, all of your hatred about this Nanao-san, could change into concern and 'omg I highly need to protect this insecure boi' kinda thing. and I haven't even talked about the teacher (but oh well, he's still a dick anyway in another Mujihi series lol)
here's link of Mujihi series to read:
http://www.mangago.zone/read-manga/mujihi_na_anata/
http://www.mangago.zone/read-manga/mujihi_na_karada/
(pardon my crappy grammar, shit I haven't slept for more than 30 hours straight and I'm gonna take it right now, I hope my words are still understandable)

Gosh, i wish we had the like button for the reply, then i would like your reply thousands times ಥ╭╮ಥ you just wrote exactly what i feel before and after reading mujihi series. I just want to protect Nanao san from all the insecure and negative thought :<<<< and Nanao san and Aikawa san are definitely the couple i love the the most out of this Warui series

Personally I still wanted someone else for him. Of course the author didn't let the uke cheat that would have ruined the manga. Personally I don't think a person like that in real life would be faithful. People that use sex for comfort can't be faithful. I don't hate the uke, just really want the best for the seme. He was my favorite character in the series.

Judging someone from their past is shallow, u act like people don't drink for comfort, drinking and having sex for comfort is the same. One can stop drinking, same as one can stop having sex with others once they have found their significant other. Your life sounds sad, have u ever met people that actually change?

If the seme were to cheat you're the type to defend someone fully knowing that they are wrong if the seme was the one who sleeps around you wouldn't be mad cause he's the 'superman of the family' and using sex for comfort isn't wrong either (unless you're in a relationship)and if you think that sex is sacred good for you but dont judge someone without fully understanding their actions.
personally this is the one story i dont like. i love nanao but i dont understand hitting on the guy you love, sleeping with him, and then giving another guy a BJ when problems crop up. had they removed the BJ scene with the teacher i would have loved this story.
i dont get if the teacher forced him into it? in which case its rape. but Nanao just kept spending time with the teacher at the end, so i doubt that. the teacher just gave me such creepy vibes.
especially how he made out with nanao right after. ヽ(`Д´)ノ
i just feel that nanao would be the type to cheat.