Hey there Cassie! It's a pleasure being able to help you out! So I'll try to answer your issue in as short of an answer possible as I tend to ramble. Okay so from what it sounds like at least from your perspective something is going on with your friend more so than your boyfriend. But before playing the blame game or automatically ruling her as trying to steal your boyfriend I'd reassess some things first! Since we typically have bias and or tunnel vision when seeing things...we tend not to see the entire story. Sometimes we may see something really negative going on, but there may be nothing at all in reality. Paranoia can do that to you in a relationship especially if you're really possessive and or jealous very easily. I've been a victim to this as well. Depending on how much you value your friendship with this other girl, I'd just straight up talk to her and see if she's really doing the things she does....if she gets really offended when you ask this may tell you that she has ill will towards your relationship. If she casually shrugs it off in a non-awkward way then she is probably just being a bit too friendly and you should then tell her that she's maybe doing too much? Then I'd confront your boyfriend about it with a scenario like "I know you've told me you'd never leave me, but I just want to be up front and talk because as a couple we should be able to be completely honest and understanding with each other and I'm sorry I've been a nervous wreck but I just want to get this off my chest....." then explain to him your concerns with your friend and work something out together. More importantly then anything the point I'm trying to get across is just communicating because in any relationship it's important to be open and express yourself. And if there's really nothing going on then they'll honestly and calmly let you know....then you can get to things like "Hey when you do this or that to my boyfriend it makes me feel uncomfortable...could you maybe not do that" and as a friend they should understand their boundaries and etc... if they get very defensive then they're honestly no friend of yours and you should find a way to maybe move on....but just confront them it's not really helping you by not doing anything and it's better to not let this drag on any further as well! Also don't compare yourself to her because your boyfriend chose you because he loves everything about you physically and inside...otherwise he wouldn't be with you or shouldn't be with you cause he doesn't deserve your time and commitment. But anyways I hope you figure things out as I've harped on a lot....just talk it out be honest calm and sincere...and just see if you can work something out! I hope that you'll be able to get these uncomforting situations to stop while maintaining ideally both relationships without any complications! But my rule of thumbs is always to do what is best for myself and those I care about not being selfish, but I mean self preserving over the things I care about.....if you love something you'll take action or speak your mind honestly to protect those things with good intentions of course! But good luck friend!