<human>: Can you condense the text into a few key points?

My boyfriend, Doug, is amazing. I have never been in a happier relationship in my life. We are equally crazy about each other, I feel so comfortable around him, and it's totally great! There is only one problem which has been popping up throughout the course of our relationship. We will call her Suzanne. I don't know too much about Suzanne, because I have never met her. Suzanne and Doug were, as far as I know, only really good friends before I came into the picture. Suzanne is super cute, and has a lot of the same interests as Doug such as video games and other nerdy stuff. Suzanne has always had a boyfriend, who apparently really hated/hates Doug. Doug told me once that he is the only person who has ever hated him. I asked him why and he paused, and then goes "...because I'm so darn good looking." So... not really quite a full answer lol. Anyway, this girl Suzanne is frequently blowing up Doug's phone and he complains about it to me a lot. she tells him what a bad friend he is. She will randomly text him demanding that he meet up with her to return some random thing of hers that he has. I always ask why she thinks he's a bad friend or something, and I haven't ever gotten a straight answer. I don't want to come to conclusions, but sometimes I'm really scared that he was just totally in love with her and is only using me to try and get over it. Things are going So well with me and Doug though that I don't want to rock the boat and bring up something that doesn't even matter. I feel insecure about this girl hitting up my boyfriend all the time though. should I just let it go and hope she kinda fades away? do I take action and be upfront about my insecurity? How can I handle this as maturely and delicately as possible?
<bot>: Girl from my boyfriends past keeps finding ways to talk to him about stupid things and it's making me insecure because I am totally in the dark about their history. What should I do?