Okay so me (M21) and my Fiancée (F20) are talking about having a poly relationship with our close friend (M21). She’s been in a mid-term poly relationship (2 years) before and knows people that had similar doubts and worries, but ended up enjoying the lifestyle and have continued long-term relationships. She and our friend had a relationship in the past and are now friends but he’s realized that he still loves her. He has had a similar relationship before and they talked about it briefly before bringing the idea to me. She has talked about boundaries they want to put in place to help me ease into, and she’s made sure that I know that I am her first priority and is willing to end it if I’m not comfortable with it. He is also willing to respect my decision and just continue being friends with us if I decide not to. However, I am a bit anxious about it because I have never done anything like it and I don’t want to accidentally make things weird between us and lose them both. I tend to overthink a lot of things even to the smallest detail, and don’t want to end up getting jealous and ruining it because I didn’t communicate. I want to give it a try but I need more information. I have done a some research already and my fiancée has explained it to me as well but I just keep finding my self getting anxious, but I do want to try. I just want more advice from people who have done it before.