Sentence 1: Tina and her best friend Britney decided to have a joint party. 
 Sentence 3: The girls rented a nice restaurant and invited all their friends 
 Sentence 4:  The guests had a blast 
 Sentence 5:  The girls couldn't wait until next year 
 Option 1: They decided to have it at Tina's house. 
 Option 2: They wanted to have a joint birthday party.