Tl;dr This comic feels like it was made by someone who's never made a comic before.
This doesn't look right at all. The layout in each panel doesn't look right and each page is inconsistent from the last. Like, in the first 3 pages, Greg is lying down, and at the start of page 4 he's sitting up on a couch or bed that disappears in the next panel. Page 5 also has bad boarding with Amethyst opening her mouth that's full of cum after she swallowed it. The backgrounds are interchange between a blank white void and a blank black void. Either way it's just lazy, especially when the show has some very homely and serene backgrounds. It's somewhat out of character for Greg not to have any dialogue in the comic, especially when it's with Amethyst, the same Amethyst who blamed Greg for "taking Rose away" and who he had an uncomfortable relationship with since Rose passed before reconciling. And Greg and Amethyst's design in the comic is from before Steven was born yet the last line, "As good as always, Mr. Universe" implies that they've been doing it for a while. And the way that last speech bubble was placed makes it look like Greg is saying it instead of Amethyst. What's worse about the whole thing is that it is so rushed. I don't know if this was commissioned by someone or if the artist got bored halfway through production, or if they were just being lazy, but 7 pages of Greg and Amethyst fucking isn't nearly long enough to be arousing, especially when it's this poorly executed. The admittedly good character designs deserve so much better.