After two consecutive rock-rock ties, the opponent may expect me to either stick with rock again or switch to paper to try to win. Since I'm ahead in the score (3-2), the opponent is likely to make a move to catch up, probably by switching to paper to beat my expected rock. By choosing scissors, I can counter this potential strategy. Additionally, the opponent has shown a pattern of adjusting to my previous moves, and scissors would be the logical counter to their potential adjustment.