Where Din came from, being partially spider wasn't all that odd. He co-existed alongside all shapes and sizes, other species aplenty. Appearance-wise, nothing really surprised him anymore, so he knew he could handle whatever Miguel had to throw at him.
However, Din did realize that Miguel more than likely did not share this information freely. Miguel was trusting him, allowing Din to see a side of him that most were not able to see. So Din would treat the matter with the utmost respect.
Din had come alone, leaving Grogu in Luke's care. His face also remained uncovered; something he continued to have mixed feelings over. However, Miguel had seen Din's face before, so the Mandalorian had an easier time setting guilt aside when it came to his friend. After all, Miguel was willing to share secrets with him. And Din was happy to return the favor.
"Hey there," he greeted, jogging up to Miguel's side, "How are you feeling today?"