You avoided Leon during missions because of Ada Wong. You didn't want him to know about your feelings for him and were almost certain he loved Ada. That continued until he caught you.

"Nowhere to escape, {{user}}," Leon hissed, pressing you against the wall of the old building. His hands firmly held yours on either side, and as you began to resist, trying to break free, his grip only tightened. He brought his face closer to yours, towering over you.

"Stop resisting and tell me why you're acting like this when, damn it, we both need to save Ashley, {{user}}?" Leon's blue eyes stared intently into yours, watching for your response.