I saw a post outside of tumblr saying that lucifer subtly looks down at alastor's mouth before pulling him closer to his face, and they had a gif of it but it was kinda low resolution, so I was like "huh, i didnt notice that, i wanna see!" and looked up the youtube video of "Hell's Greatest Dad". Here is a gif of that moment:
Now, the reason I felt the need at all to make this post is because the low quality gif that person had posted clearly showed Lucifer's eye glancing down, supposedly at his mouth, before flicking back up to Alastor's eyes. But that's not entirely the case.
Here it is slowed down:
As you can see, Lucifer's eyes were already looking down at Alastor's mouth as Alastor began to shout "I'm singing it-!" before flicking back up to his eyes as Alastor got physically closer with "-I'll FINISH it!".
This tells me that that low quality gif shown by that person was doctored.
I'm more than okay with people shipping what they want to ship, but you don't need to spread misinformation to make it "valid".
And if you need to see for yourself, then go ahead and watch the music video:











