[His faux-innocent look is probably not fooling anyone, despite the actual cross he draws over his heart. But there's definitely a smile tugging at the corner of his lips, too...
... and very admirably it doesn't even widen when he listens to his dumb bf's silly talking-singing for perhaps a whole half a minute before quite simply leaning in and kissing him. That is enough singing for the mistletoe, surely, and he really, really needs to give Art a kiss right this second.
And, pulling back just slightly:] You may not be winnin' any singin' awards, darling, but you sure as hell are adorable.