I(27M) lied to my partner(28F) and I want to come clean.

TLDR; I lied to my gf about how many times I had contacted my ex since we had started dating and I want to come clean.

First of all, I admit that I am 100% the wrong one here. I do not want to try to make myself a victim by using a word like "mistake" or whatnot. I want to come clean about my lie and would like to hear about other opinions on whether it's a good idea or not.

My gf(28F) and I(27M) have been dating seriously for 10 months now. Before I started dating my current gf, I was in a 3 year relationship with my ex and then broke up.

My ex and I, when breaking up, didn't try to "stay as friends" because that is ridiculous, but we agreed on not blocking each other as if any of us did something unforgiveable. (it was a beautiful relationship but we had to break up because we couldn't see how we could manage long distance longer.)

We broke up months after we saw each other last time in person, so obviously we had no other option but breaking up over the phone. I knew we were not getting back together ever again because of the situation that had made us break up. So soon after the break up when I met my current gf who is a wonderful person, I started dating.

When we started dating, I wanted to open important parts regarding my past relationship, but my gf said she didn't want to hear anything about my past relationship or my exes. So I said I would respect that, and we never really talked about any ex related topic.

I texted my ex from time to time even after I started the new relationship. It was never about trying to get back together, nor we exchanged any kind of sexual text. I used to ask her how she was doing, she would ask me too, I used to text her when I realised she still had picture of us together on her social media and reminded her to delete those. And we used to remind each other why the breakup was inevitable, but that we didn't have any ill emotion towards each other, wish the other the best, and stuff. This happened like once every 2months.

Once, my gf and I had a huge argument. She got very emotional and was almost breaking up with me. Then she randomly asked me if I had ever contacted my ex since we started dating. And I lied to her it only happened once a little after we started dating, even though it had happened two more times after that.

I lied because I was afraid if I told her it had happened multiple times she would leave me right there. Still this cannot justify what I did. I am a horrible person. That day she told me she wouldn't want me to contact my ex ever again, and in case my ex reached out to me first she would want me to tell her. I promised I would.

And as I promised, I've never contacted my ex ever again. At first I thought maybe I should tell my ex I'm cutting her off because my gf doesn't want us to stay in contact, but that would be breaking the promise so I just disconnected my ex from all kinds of messengers and removed her contact. And so far my ex has never contacted me first so I never had to tell my gf about this.

It has been 2 months since I lied. Do I think there is a high possibility that I will get caught in the future? No. I completely removed my ex's contact along with the chat. But still, even though I already did something wrong, I think the best I can do out of respect for her is coming clean and apologize. I plan to tell her everything, exactly when and why I contacted my ex, and what we talked about. I know the consequence might be... her leaving me but it is true that I don't want to lose her.

I saw this type of advice on another subreddit though, if I am 100% certain I will not repeat the same thing again, I should rather not come clean because that will only relieve my sense of guilt but totally destroy the partner's feelings. And many people were agreeing to this, so I am now confused if my plan is an even more horrible act.

Can you guys give me your opinion on this?