My gf(21F) is upset over something that happend 2.5 years ago(22M)

Hey everyone. I (22M) have been with my girlfriend (21F) since we were 17. We basically grew up together, and she’s the person I respect and love the most. We had some small issues in the very beginning, nothing dramatic, mainly about social media boundaries.

Back then, I was one of those people who just mindlessly liked everything on my feed or explore. I didn’t think twice about it. I also followed a few TikTok girls, the same way she had her celebrity crushes, she was crazy about them and she was followed them as soon as she thought they were good looking. When she told me it made her uncomfortable when I like random girl posts on explore(never something vulgar) or kind of thirst traps of the influencers I already followed, I stopped immediately. Not because she forced me to, but because it mattered to her. Since then I’ve been very conscious about what I like online, and honestly I don’t even think about other girls. She’s my person.

Now here’s the issue. About a month ago, she and her friend were looking at a profile of some girl from our town, not someone we know personally, just someone you see around. While scrolling through the girl’s older posts, they noticed a like from me on one of her pictures. The picture is old, posted during a time when my girlfriend and I were already together for almost a year, but before we fully talked about boundaries. The photo itself is normal, nothing revealing, just her in front of a Dubai view.

What confused my girlfriend is that I never followed this girl, I don’t know her, we have no mutual friends, nothing. She remembers that once, years ago, she told me to check out a cool picture on that girl’s profile. I vaguely remember that too. It was honestly the first time I ever saw that profile. When my girlfriend asked me about the like, I told her I genuinely don’t remember pressing it. It was so long ago. I checked the date, it was liked the exact day the photo was posted, which confused me even more. The only things that make sense to me are: either I saw it through explore, liked while scrolling, or I accidentally liked it when checking the profile because she told me about that one picture. I know myself, I used to randomly like stuff without thinking, not just girls, evedything. I still sometimes accidentally tap things when scrolling. It’s not impossible that this was one of those mindless likes. I would never itentionally like local girl's photo to get her attention, I think there are better and less weird ways to do that if someone wanted to, and I didn't.

But she’s been really anxious about it. She feels like she was “stupid” for trusting me back then, even though I’ve never done anything shady, never messaged any girl, never liked her story, never interacted with her again. Nothing. It hurts because I see how much this bothers her, and I don’t know how to make her feel safe again. I’m not defensive, I’m not hiding anything, I just truly don’t remember liking that photo, and I’m frustrated that something so old and meaningless is making her feel insecure now.

I want to reassure her, but I don’t want to dismiss her feelings either. I know she’s sensitive about these things and I want to be supportive. But I also don’t know what else to say besides the truth. How do I calm her anxiety? How do I show her this old, random like means nothing and never did?

TL;DR: My girlfriend found an old IG like. I don’t know the girl and don’t remember liking it. It was probably accidental/from Explore. I stopped doing that years ago when she said it bothered her.