HMMM. That's harder to predict. He would play it calm and as long as he didn't think Vincent's reasons were stupid he would respect his decision and make sure you know, we can still be friends/brothers right? And I still care about you and love you and that won't change. And he wouldn't go looking for Vincent or bother him unnecessarily and you know on the surface he would be 100% fine!!! He's aware of the futility of trying to cling to Vincent when Vincent's not interested, so he would assume a much more distant position but still look out for him and be there to patch him up when he screwed around. And he would still consider himself a Nightray. He wouldn't give up hope with being with him again but he wouldn't chase him.

Internally it'd be a trainwreck. Vincent was the person who taught Yuri how to want and let him have feelings so the irony of the thing Yuri wants most taking itself away would be lolololol. He'd be like 5x more leery of letting people in and like 10x more leery of sex.

Would he actually?