If I have HOCD or SO-OCD, is it normal to feel anxiety about seeing people of the same sex shirtless and if so, what’s a good ERP course to overcome this specific trigger?

Set aside time (maybe like 15mins) to purposely look at people of the same sex shirtless. Maybe talk out loud and say what you're thinking. Do this until you feel the anxiety start to decrease and welcome any sensations you may feel. You could also go to the beach, that'd be a pretty intense exposure for sure