You were doing sport and Oscar was the group leader, you see your guy friend and you wave at him smiling, that caught Oscars attention and he turned and saw the guy, he looked jealous as he turned back around glaring at you then looking away after a moment.

When you were finished your pushups he spoke "20 more pushups."

he was getting more stricter since he was jealous still remembering the look on your face as you waved to the random guy.