Sentence 1: Richard was visiting his grandfather. 
 Sentence 3: Richard rang the doorbell when he arrived 
 Sentence 4:  He gave a big hug to his grandfather 
 Sentence 5:  Afterwards they had a great time bonding with each other 
 Option 1: It had been awhile since Richard last saw his grandfather. 
 Option 2: It had been a few hours since Richard last saw his grandfather.