Complex sentence: Nevertheless, Arjun takes this insult in his stride and narrates his love story to Tarun, who is unaware that Arjun is actually telling Tarun his own love story with Poorna, rejoices in the many twists and turns that Arjun endures to win Poorna'a love.
Split into simpler sentences: Nevertheless, Arjun takes this insult in his stride and narrates his love story to Tarun, who is unaware that Arjun is actually telling Tarun his own love story he shares with Poorna. Traun rejoices in the many twists and turns that Arjun endures to win Poorna'a love.