Boyfriend didn't tell me our friend is his ex.

Dear Lori and Jeff,

My boyfriend and I have been together for a little over a year. We met when I moved to the valley from the west coast. I didn’t really know anyone in this new community and I really enjoyed his group of friends so I quickly became part of the gang. A few weeks ago I found out that my boyfriend had had a pretty intense relationship with one of the other women in the group but no one, including my boyfriend, bothered to tell me about it. I don’t feel like I need to know their entire history, but the parts that could affect me in the present day seem to be important information for me to have. He says it’s in the past and he no longer has feelings for her but I think I should have been told as our relationship became more serious. Any thoughts?

Signed, Unknowing Friend Of His Ex