I [M19] saw my ex [F19] a few weeks after cutting all interaction with her and ....

...I saw her driving two nights ago. It was 12:30, and I just got the notification that it just turned her birthday.

We drove right next to each other for a bit while I was in a distinguishable friend's car. I put my arm up and made myself tiny as we drove past but I believe she definitely knew it was me. My friend in the back said she saw us and smiled.

Either way, I didn't say happy birthday to her. Now I'm regretting it. I don't hate her nor will I ever, but I feel terrible for not saying it.

It's not like I was asking her to hang out or see me or something - it would have just been a simple "happy birthday" as we drove past and I couldn't even do that. In the moment I didn't even think about doing it, only afterwards was when I felt regret.

Still no contact! But god damn I feel like a terrible person, even wanting to text her happy belated birthday or something. I know I shouldn't, but I wanted to know what you guys think.

Part of me thinks it's my reptile brain trying to trick me one more time, cause we dated for so long. But it's not beating me up nearly as much as originally deciding to stop talk to her. But this current event has made me start thinking about her a lot, rather than having her on the back burner which is how it was (finally!) starting a few days ago.

Thanks for reading

TL;DR: Saw my ex driving 30 minutes after it turned her birthday, just ignored her