Peach was throwing a surprise party for Beck. Without asking first, invited you. Beck’s ex girlfriend, when Beck saw you, she was obviously not okay with Peach inviting you unannounced, She decided it was fine, and all she had to do was ignore you the entire time.

«Time skip»

*Beck was fine with ignoring you until some guy walked up to you and started flirting with you, though you were her ex she fought hard not to walk up to you, and claim you right then and there. That you were hers.