So about a year ago I was paired up with this girl (who I will call W) for a project in my biology class. As we are working I start to just chit-chat with W about stupid things and videogames come up. To my utter suprise she is a avid gamer and it happens she also plays xbox. She is really into fallout and so am I. We then end up going back and fourth on Instagram about fallout 76 hype and other gaming stuff, and I would send her hella memes. We play often, and I have her favorited on xbox (this is important later). During this whole time my gf of a year and a half asks for my Instagram password and I willingly give it to her. So about a week after I give my gf the instagram password I go to send W a meme I made and I cant find her anywhere in my recent dms, I just think its a weird glitch and go on with my life. Later I go to unblock a different friend of mine after he spams me with 400 messages (he has done this several times after I smack him in for honor so now I just block him when he does it) and I see W on my blocked list. I wondered how she got there for a seccond but eventually just think nothing of it. I unblock her and go on with my day. A few hours later my gf calls me sobbing and asking why she isnt good enough for me and all this and that, obvoiusly im confused and ask her whats going on. She yells at me for unblocking W when "clearly" she has a problem with her. I dont know what really I did so I hung up.
Now everytime I try and dm W she is blocked, and gf will always get mad when she sees the notification that W sent me something. I threaten to change my instagram password if Gf keeps getting upset over the simple jokes and stuff we send to eachother. And then she gets even more upset, so I get even more upset. But I can see where she is coming from. She has told me several times that she is jelous that W and I have more in common than gf and me. She also told me that W is more attractive than her and I honestly agree, but I do love my gf and it hurts me that I have to hide my friendship with this person because its driving a wedge in my realtionship. 
In the summer gf comes over and we put up netflix on the Xbox, about 30 mins in I hear the notification  *ding* that it makes and look over, W just came online. Gf gets really mad that I stoped paying attention to her to pay attention to the xb. But then she sees who it is that I looked over for and she slapped me saying "why that bitch on your xbox" I try and explain why but she dosent want to hear it. So I get angry at her for always doing that and that I just want to have some friends. She told me that I can be friends with anyone but her. This arguement ends how it usually does when we argue about W. Gf just ends up leaving in a bad mood. 
When school started back up in the fall me and W have a class together and gf and I have none. This reaply tilts gf and it brings up another arguement about things out of either of our control. There is nothing either of us can do so we let it be. The first day rolls around and since me and W know each other we sit together in class to talk and what not. The gf hears about this and goes all out when I see her. I end up just getting sick of having so many arguments about W that I change my insta password and go out of my way to not see gf for about a week to let things cool down. This was the wrong move in hindsight. Gf gets dumb mad about that and turns out she been going at it with W over Snapchat and insta the whole week. I dont know If im just acting childish or she is.
About a month later me and gf chillin by my locker after school and W walks by, and I think to start somethin she says " thanks for that color pack in warframe, im a broke boi so you came in big clutch with that gift." Gf really didnt like that because I told her me and W stopped playing games, which was a lie. So of course it starts a arguement later and at this point I am done with all this so I just roll over in bed and ignore her till she gets tired and leaves. 


TL:DR: me and this girl play games and send eachother memes everyday. But my gf dosent like it but against her wishes I do it anyway