AIO: accidentally saw messages on my girlfriend’s phone suggesting very surprising behavior. I ended things immediately.

I (early 30s M) had been dating my girlfriend (mid 20s F) for about 5–6 months. I cared about her a lot and was treating the relationship seriously. We had taken trips together and were even planning an international trip in about five weeks.

Yesterday something unexpected happened that led to everything blowing up.

My mom was visiting and my girlfriend was saving my mom’s number in her phone. There was a mix-up with the contact and my girlfriend handed me her phone and asked me to fix it while she went to the bathroom.

While I had the phone open in messages trying to fix the contact, I noticed a message thread with another guy. I didn’t go digging through the entire phone, but what I saw in that thread immediately raised red flags.

From the messages I saw:

• She had been Snapchatting this guy nude photos/videos for money

• The messages referenced him paying while she sent sexual content until he finished

• There were discussions about meeting up at a hotel for “an hour or until he finishes”

• There were Apple Pay transfers totaling roughly $10,000 over a couple years

• Some of the earlier messages involved negotiating prices for photos/videos

Some of these messages went back a couple years (before I was dating her), but there were also payments and communication happening while we were actively together.

What bothered me most was the timing of some of it. For example, I saw messages that happened late at night while we were traveling together in NYC. Another Apple Pay exchange happened last month the night before we went to Hawaii for her birthday.

When she came back from the bathroom, I didn’t confront her or start an argument. I simply took her home, dropped her off with her belongings, and told her something along the lines of “looks like you have a business going for you, I wish you the best of luck.”

Since then she has emailed me claiming she has no idea what I’m talking about, saying she was always loyal and that she doesn’t have any kind of “business.”

Instead she’s focusing on how I ended things and saying it was unfair that I didn’t explain what I saw.

From my perspective, once I saw those messages and payments, the trust was gone immediately. I didn’t feel the need to sit down and debate it.

But part of me wonders if I should have confronted her directly and at least heard her explanation.

Am I overreacting for ending the relationship immediately after seeing that?