I’m nervous that my fiancé might cheat on me.

So my fiancé and I are going to be getting married in a few months but one thing keeps digging at me and it’s this friend she has. My fiancé and him went out once before they realized they weren’t attracted to each other but they’ve kept in contact. Our entire relationship ever few weeks or so she calls him and talks to him for hours and they text too a lot. I wasn’t worried until recently when he broke up with his girlfriend and is texting my fiancé about it. She assures me that she loves me and only me but I can’t shake this feeling like it’s leading to disaster. One instance is he came over a few weeks ago with his gf to my fiancés house and she silenced her notifications and wouldn’t respond to me at all. Idk what to think. I’m super nervous and I can’t shake the feeling. I’ve met him once btw. What do you guys think?

UPDATE 1: Thank you for all your support and comments. I talked to my fiancé about the post and about how I need my worries talked about. She sent him a message basically telling him she doesn’t want to talk to him anymore, but something felt wrong about it so I had her go back and explain what happened and he reached out to me personally and ask to call. Tonight I’ll be talking with him. What type of response should I be looking for to confirm that they are just friends and what red flags should I look for?

  Update 2: I talked to him and we talked for an hour or two. Idk how to explain how relieved I am. He is really cool and I feel I overreacted (not to say I’m still not cautious) apparently he and his gf are still together they’re just on a break he loves her so much and he doesn’t want to marry or be with anyone but her but shes been focused on school and is to stressed to really appreciate him so he’s decided they needed a break. I knew deep down that nothing was wrong but I let my insecurities and thoughts of everything cloud my judgement. He is an amazing friend to her and he just wants what’s best for her. They’re like brother and sister and he sees her in no way shape or form as a partner. He said he needs a rock and that she couldn’t give that to him. He also said other things that I don’t want to repeat but I know he won’t make a move on her. I set boundaries and he’s agreed with them my fiancé has also agreed to them. I’ll be talking with her more tonight I’ll update again but idk how much I’ll repeat back. I’m really really happy with my fiancé and I’ve trusted her all along. I know she loves me and couldn’t cheat on me I know by the way she looks at me by the gifts she gives me and more then all of it she chose me and not him. She’s truly the love of my life and I couldn’t have chose a better partner. I guess deep down I don’t feel like I deserve to be happy and I guess couples counseling and counseling should be an option. I want more than anything to marry her and to make us work but I have to work on myself too. Thank you for all of your comments. I read every comment and leaving felt like a mistake I’d regret for the rest of my life. Tell me what you guys think. I’ll update more when I talk to my fiancé

Update 3: I’ve seen a lot of comments saying that I’m naive or that I’m a troll let me clarify a few things. He lives 2 hours away, we have tracking enabled on our phones, he told me that she is to anxious and not able to be his rock for him, also he said she’s not his type in anyway shape or form. Second she’s been apologizing profusely for not taking my concerns into account sooner. She and I are on the phone basically every day for as long as we can be because she lives and hour away. He lives 4 hours from me and 2 hours from her. She works part time and goes to school full time. He works full time and goes to school full time. Boundaries I set and her agree to: they are not allowed to meet without my knowledge or in private, I can check her phone anytime I feel I need to have concerns addressed and she can do the same, we are %100 about everything, if she has concerns she comes to me first, they aren’t allowed to communicate on any other form besides texting and calling, and finally we need to trust each other and tell each other everything.