Last night I got home past ten, dead tired from doing management accounting all day and driving back from downtown Nakhon Ratchasima. It was drizzling and traffic sucked. But when I climbed the stairs to the third floor, everything felt different — weirdly quiet. So quiet I could hear the wind through the window.

I didn’t think much at first, figured my girlfriend had gone out to buy food or for a bike ride. But when I opened the door there was a pair of shoes by the sofa that weren’t mine. I just stood there dumbfounded for like five minutes. My hands were shaking and I don’t know why — I’m actually pretty calm by nature, almost forty, an accountant, nothing flashy. But my head suddenly went “huh” out of nowhere.

I walked into the kitchen and saw a coffee cup and a food container that wasn’t cold yet. That made me overthink even more, so I grabbed her phone that was on the charger just to check what time she’d come back. The lock screen had a passcode. I stopped and thought for a long time whether to open it. Honestly, I’ve never been the nosy type, but my heart wanted to know so badly. In the end I typed in a code she’d once asked to borrow when she forgot hers — and it actually unlocked.

I couldn’t believe my eyes. A chat came up with a name I’d never heard before, and the profile pic was clear — a woman. The messages sounded familiar and intimate, little sweet things, calling her by a nickname she never calls me. Reading it felt like getting slapped. I kept telling myself not to jump to conclusions, but each line slapped into my head saying “what is this?”

There were messages about meeting up, and one telling her to cancel plans with me — on a day we’d planned to go make merit together. That didn’t match what she tells me every day about liking family life and simple things. She once said she liked it when I cook near the alley. We used to laugh together, but this behavior looked like a totally different person.

My head’s a mess. I don’t want to drag her up and confront her, I want to talk, but I’m scared. Why scared? I don’t know — scared that the truth will ruin everything, scared I’m not good enough, scared I’m being too naggy, or that I was stupid for trusting too much. Ughhhh, the feelings are so confusing I don’t know where to start.

This morning I chose not to bring up last night. No questions, no suspicious looks. Maybe there’s a reasonable explanation — a coworker or a relative visiting. But then I wonder, why hide chats, why delete call logs, why have couple photos? Some pics were blurry but you could tell it wasn’t just old friends. It felt like there’s another life I don’t know about.

Over the past week I’d noticed small things I’d overlooked: she’s on her phone more, sometimes laughs alone and quickly locks the screen, comes home later than usual saying it’s work or friends. But my accounting team friends say they’ve never seen her working late like that. I’ve tried to gather more logical evidence, but the more I look the more it hurts.

Logic and feelings keep clashing. Part of me wants to believe she just made a new friend, the other part feels like it’s being torn in two — one side wants to keep our life, the other wants to face the truth. I keep asking myself whether I’m just being possessive or should give her space. But if that space comes with secrecy, it hurts.

Honestly I know that confronting her suddenly could blow things up. I don’t want to yell or make a scene. But if I stay quiet and it’s true, do I wait until I can’t take it or am I overthinking? I’m really confused — can you folks give me advice on what to do first — wait it out or tell her calmly and directly? Should I get concrete proof first, or just face her and ask straight up? I’ve got financial responsibilities and a steady job, I don’t want personal problems to wreck our lives, but I also don’t want to be lied to forever.

P.S. I want opinions from people who’ve been through this or older folks — what would a near-forty-year-old guy like me do? Maybe I am overthinking; sometimes the reasons are small but the feelings are huge T_T

OP here — what should I do?