Not graphic though and as far as I know never with the main character. Not even fade to black I think.
Note that the red prince is the only character you can't have intimacy with in DOS2 and he himself only sleeps with another lizard?
They changed that in the re-release, you can romance and even sleep with him, but he still third-wheels you unless you never do Sadha's story.
Also, sexual attraction to a sentient anthropomorphic lizard/dragon falls under teratophilia, not bestiality, I'd love a Dragonborn companion actually, but I'm not going to get into why it would be a bad idea for larian to make the only aspec companion also be the most inhuman looking one.