<human>: Give me the gist of the text in a nutshell

So my boyfriend and I have been dating on-and-off for two years now. Our relationship has been pretty good, but some things have come to light that I'm not so comfortable with.

Basically, my boyfriend has this close friend that he dated years before me; she dumped him back in high school and has been with her now boyfriend for many years but has a history of infidelity. Every time she comes into town, he basically drops off the face of the earth and they catch up until she goes back to college.

During a recent (and our only) break, he spent about a week with her, sleeping at her place, and she posted pictures of them going out to dinner, hanging out, etc. I didn't think too much of it at the time, obviously. I figured they were just hanging out as friends. He later admitted to me that he was hoping to rekindle something between them during this time.

When we started seeing each other again, she asked him to be her date to a wedding this past December. He agreed. I was not invited to the wedding so I don't know what happened there, but according to a few of my friends who were there, they kept sneaking off to be alone and danced pretty intimately in front of everyone.

Every time I ask him about her, he tells me that she's not even that good of a friend, and they only hang out because she nags him about it whenever she's in town.

I've checked his phone and Facebook since then, because obviously these rumors make me nervous, and there are no threads between them. None. At all. These are two people who are immensely close, and I can't even find a single message for how often they are in contact.

I've never had a reason not to trust him until now, he's never cheated on me or lied (that I know of) before.

Am I just being paranoid? Should I bring this stuff up? What should I do?
<bot>: I have reason to suspect that my boyfriend is in love and maybe even cheating on me with his close friend from high school, but I have no physical proof other than what I've been told. What do I do?