Well I can understand Jinhee's side.. It's probably Jinhee wants to move their relationship to the next level besides convenience but it seems that his bf might not be ready yet.. Jinhee might also be feeling insecure and lonely when alone since being in a mono relationship is new to him but atleast he really is trying to get seriously with him thus, by doing that on an impulse although yeah, he should've had discussed it first with him before making a move and respected whatever the outcome is.