Is it wrong to date your ex's good friend????

Me and the ex never really officially dated and me and his best friend hit it off since the moment we met; the ex would literally other himself if all 3 of us went out because he was so socially awkward. I never really liked him and he knew that, he knew I didn't reciprocate the same feelings that he did. Me and his best friend get along so amazingly, we told each other we love each other already and it's been less than a month of us officially dating. It's crazy but we both are really invested and serious about the relationship but we have so much fun together. I can literally see the rest of my life with him. The ex doesn't know yet because he's in Poland, I'm worried that he will think that's like against bro code but I also don't give a fuck because I love his best friend...what do y'all think??