Complex sentence: The final straw is when Alisha sees Rajiv and Payal talking, and she comes to know that both of them were together before she entered the college, and she confronts Payal and behaves rudely with her, and accuses her of stealing her boyfriend.
Split into simpler sentences: The final straw is when Alisha sees Rajiv and Payal talking, and she learns that they were together before she entered the college. She confronts Payal, behaves rudely with her, and accuses her of stealing her boyfriend.