Stiffness/discomfort in a social setting
If you do convince him to go to a party with you or some social setting, he’s clearly uncomfortable. He may even seem upset. He makes no effort to mingle or chat with others. He takes a seat in a corner with a drink, waiting for you to finish socializing. Maybe he even keeps an eye on you. Clingy partners often struggle to enjoy being with you in a social setting. They just see others as a threat. Other people are competing for your attention, and clingy partners don’t like that. A clingy partner will make you feel guilty that you dragged him to a social setting.