Shen Yuan considers it and consciously chooses not to look behind him to see whatever's causing Lan Xichen to blush so hard (assuming that is a blush and not some other Coldblood reaction, anyway...). If it's someone wearing shortsleeves or something like that, well. He just needs to get used to it! And making him talk about it will just be embarrassing for them both.

(It does not occur to him to connect Lan Xichen's line of sight with his own face. This does not even register as a possibility in his comphet-chugging little mind.)

Instead he laughs, delighted by the mental image of a master cultivator playing Candy Crush, of all things, and says, "Lan-gongzi is getting used to the omnis so quickly! How far has he gotten in Candy Crush, may this one see?"

Show him your high score, Lan Xichen. Show him your high score!