Phew. Well, first things first, I'm glad that it wasn't simply left at him deciding to stay. Decisions like this actually influence both the work and the relationship, as we see in this chapter.
Secondly, it's good to see that Aoko doesn't actually support him dropping such an opportunity, despite all her anxieties about him going.
The tricky place, though, is where Tatsuki is at right now in all this. You know, when you technically have no obstacles preventing you from doing the thing, but you just know that it will worry and possibly hurt another person, even though they still sincerely want you to do the thing? It's a very suffocating situation to be in. You feel like you lose either way, but at least in one way it won't affect your loved one.
...Except a person who loves you wouldn't want you to hold back and pass on important opportunities.
So, a tough moment right there! And realistic, I sure have went through similar things in my life. So I can relate.
I know everyone in the comments is annoyed at them not coming up with a simple solution of going together. But it only sounds simple on the surface, and even though it wasn't established yet if this option is possible in the story or why not if not, I think we'll get to that in the future chapters.
Thanks for the translation!