Need help: I lost track on a manga I found intriguing-

it had a slight dystopian setting and focused on 2 male leads who I think were traveling together. What made their relationship atypical and complex was the fact that one was a pre pubescent boy and the other a grown man. I remember their relationship had sensual/sexual ambiguity/nuances and ambivalent complications. However it majorly stayed platonic and the older man was mainly platonic in his affections and protected the boy.

Thank you if you can help =)

Sounds a lot like Kalyx: https://www.mangaupdates.com/series.html?id=98580

It looks intriguing and I will want to read it, thank you!

It has an interesting setting and relationship, only thing is, she's a young girl rather than boy.

Thank you though!

Stigma by Minekura Kazuya