I'm a 30-year-old woman, and I'm having a disagreement with my 29-year-old partner about something rather trivial.

Recently, I found myself overdrawn by $30. My partner has been dealing with financial challenges, so I decided to ask our roommate [32M] if he could lend me a few dollars. We've all been friends for about five years and have lived together for the last two years. In fact, our roommate is going to be my partner's best man at our wedding next year. He and I have a good friendship and we're part of a group chat that includes all our friends, including my fiancé. I texted our roommate separately one day to request the money, and I promptly paid him back two days later once I received my paycheck. Not long after that, I was relaxing after a long day when my fiancé approached me. He said, "Since you haven't mentioned anything, I’m just going to bring this up. It doesn't seem like you were going to tell me." I was taken aback and confused. He then asked, "When were you going to tell me you borrowed money from [insert roommate’s name]?" I replied, "Why would I need to tell you? It was a small amount, and I already paid him back." Since then, we've been arguing about this. He doesn’t understand why I didn’t tell him because it relates to finances, although we don’t share an account. I feel frustrated because it seems like he’s implying I’m hiding something scandalous from him. He even got upset with me for leaving a basket of dirty laundry in the hallway, saying, "Do you want someone to see your underwear?" It's been a series of little comments and actions that have worn me down, and I'm really tired of it. Maybe I'm overreacting or taking his words too personally. Should I have approached this situation differently?