Sentence 1: I came to the party with my family. 
 Sentence 3: However, they ended up finding each other except me 
 Sentence 4:  They also left the party before I found them 
 Sentence 5:  My friend had to take me home from the party 
 Option 1: Since the place was crowded, I lost contact of them. 
 Option 2: We left together after ten minutes.