<human>: Can you give me a shortened version of the text?

**A little bit of backstory:** My boyfriend was in love with this girl for a good 5 years before we met, but his feelings for her started dwindling soon before we started talking. It was unreciprocated love; she never gave him the time of day romantically. He still sees her on a semi regular basis due to the fact that the have a class together a few days a week (a class that she coincidentally transferred into according to him.) He admits he still has "very slight" feelings for her, despite being in love with me and in an exclusive relationship with me. Every now and then a mutual friend in the class will post pictures and in some of them he's very close to "that girl" physically, which I find unsettling. 

**The issue:** Two months ago, a month before we officially started dating, he said he was going out with a group of people to a river for his male friends' birthday party. I found out last night by chance through one of his friends' instagram accounts that it was, in fact, "that girl's" birthday and he lied about it.  

Additionally, 2 weeks before we started officially dating, he said he was going school clothes shopping with a male and female friend of his, which was true. What he DIDN'T tell me, was that "that girl" was also there, which I also found out from that same instagram account. Not to mention he totally disappeared for HOURS that day out of nowhere.  

Keep in mind that although we weren't dating exclusively at the time, we were already heading there and were totally invested in each other romantically already.  

**My problem:** I don't know if I can trust what he says regarding this girl anymore, in regards to the severity of his feelings for her, how often they really see each other, and how close they are anymore. What do I do?
<bot>: Soon before dating exclusively, my boyfriend lied about being with a girl that he used to be in love with and still has slight feelings for.