[It's easier to cope with Yamaguchi moving in when he more or less expects it, so he catches himself before he tenses up. Hesitantly, awkwardly, he reaches up and rubs Yamaguchi's back in small circles.]

Yama-chan, I like you and I like drinking just fine. But can you tell me you wouldn't be uncomfortable in the morning if I did anything with you?

[Even if he started now it would feel too much like he was drinking to ease his conscience rather than to have an enjoyable evening.]

Another time we can drink together but I don't want you to regret anything. [He takes a breath.] I like you too much for that.