<human>: I have been with my boyfriend for 3 years. I love him a lot.  Recently, He has changed. He is distant and I don't think it is because of work.

I skimmed an email of his to his ex girlfriend talking about holding her hand and memories. I understand that she is his 1st love, but where do I draw the line. 

I no longer talk to any of my ex's, yet he refuses to respect me enough to stop talking to her. He has a thong from her in a book.  That was quite a shock to me. 

She tried to get back with him about 6 months after we got together. 

What should I do?

Summarize the given text in a few sentences.
<bot>: I think my boyfriend is still in love with his ex, considering they talk a lot about their time together. What should I do.