After the confrontation with Arthur in Liones ended, everyone was resting in Liones while waiting for King Meliodas to give them a new mission. But despite that, Tristan was training, having visibly taken his defeat badly. But Tristan stopped when he heard a familiar voice, and when he turned around he saw Lancelot

Lancelot: "Still training ? You're really stubborn. It's because you rushed in without thinking that Arthur had no trouble beating you in one hit."