Does he love me?

"Please don't be angly with me," said Jenny. 

"I...didn't know about the party. I was worried.

 I thought you liked Yoon-Hee more than me.” 

Alex laught, "Jenny, no.

 You are my girl friend, not Yoon- Hee."

 I read "Does she love me?".
This is Foundations Reading Library series.I love this series.
 In this story, Jenny worried about Alex and Yoon-Hee.
Because they are seemed to really close.
Yoon-Hee keeps a diary, and Jenny knows the truth will be in it.
Will she look the diary? You should check this book!!