I[20M] think my girlfriend [20f] is cheating on me.

I have been dating my girlfriend for 6 months now and it has been a bumpy ride, at a point she asked for space but came back the next day and I did not think it was unusual. However, my best friend [20f], Lia, and another friend [21m], Jesse, believe that she has been cheating on me.

To start with, in mid December, I travelled for swimming competitions abroad, however, on the day after I left, she told me she was going for a concert with her girl friends despite having coursework that was due the next day, I tell her it’s okay to go but please be back to your hostel by 11pm so that you do your coursework. That night, she stopped updating me on what was happening at 11.30pm. I found out she went to a popular bar open on Sundays after through a snap that was sent to me that had her, and a boy, posing together doing that love hand pose.

I panic, it is 5am when I found out and too make it worse, I had missed calls from Jesse, and texts saying he saw her at the bar, asking if she had let me know, which she hadn’t. I panic even harder. Jesse says she saw her with some guy, who was buying for her drinks and was unusually being close to her.

I end up calling Lia, who had also gone to that bar that night and she says she saw my girlfriend, and everything was okay and this calms me down, my girlfriend however says no word about it. I confront her about the snap however and she says the boy was her male best friend, however, she had never told me about him, but I pay no mind to this. Also, she Facetimes me that day twice, which is extremely unusual because she never calls unless it’s an emergency, and she tells me she misses me, again I pay no mind to this.

Fast forward a few weeks later after these competitions when I get back to the country, I talk with Lia and she claims my girlfriend has been cheating on me. She starts by saying she(Lia) talked with her friend, Jeffrey, and Jeffrey asks her if I was actually dating my girlfriend, to which she confirms yes. Jeffrey then explains to her that he has been flirting/talking with my girlfriend for about 8 months, and she at no point informed him that we were dating until one of her friends told him, he did not bring up the topic to my girlfriend and they have still been talking/flirting.

Lia also adds on and tells me she lied to me when I travelled abroad to keep me “calm” for my races at the gala, she says at the bar, she saw my girlfriend talking with this new “male best friend” of hers and they both disappeared for a while, and then re appeared, before she decided to leave the bar, without him. She said she made research on this friend of hers, and she stays and studies in another country, but has been pursuing her for a year now, apparently, but is always visiting her.

I do not know if this information is relevant to this post but yesterday, I posted a status update on my WhatsApp, but it was a tweet about infidelity and she instantly responded to it, which is unlike her because she does not respond to my statuses and she posted one on her, a joke about if you leave me, the door is open, and the door was a brick wall. I responded to it also, and she said you’re stuck with me. She deleted that status update immediately after I replied.

I don’t know what to think right now, my thoughts are allover the place but two of the people I trust believe she’s been cheating on me and my gut thinks the same. I know the best and most mature way to deal with this would be to talk to her about the whole situation but I don’t even know where, when and how to bring it up. Any advice would be appreciated.

TL;Dr: My close friends say my girlfriend cheated on me recently, and is currently flirting with someone else, and everything points to that being true.