My ex bestfriends babydaddy ?

VERY long story short i have a guy bestfriend (SJ) who i have been friends with for about 8 years now . well 6 yrs ago he had me introduce him to an acquaintance of mine. They soon became a couple and dated for about 3-4 yrs. Well during that time me and the girl (DB) became very close friends, seemed like family we hung out everyday for 4 yrs told eachother almost everything and they both ALWAYS came to me about nd for advice on their relationship problems. All they did was fight . she would act crazy then cry about everything, he would be nice then mean. Well SJ came to me one day about a yr nd a hlf ago and said he had more then "friend" feelings for me . i brushed it off a couple times, well the about the 5th time he began to give me explanations, i had never had feelings for him but we did have a special friendship. Well me and DB fell out a yr ago because i found out she was being really fake behind my back. well Me and SJ are currently talking like we kno WE are what we want in life.hes really a gentlemen verygood head on his sholders very responsible and caring. But i feel like its very wrong in a way .... And they also had a child, she got pregnant on purpose and now acts like crazy bm. She said she doesnt care what happens she will never let him be happy without her. Lol But its like me and SJs relationship is more then just lovers (now) , we were bestfriends for so long we kno everything about eachtother. What we like dnt like ,foods ,colors ,clothes,vibes, pasts,plans, never run out of conversation , kno every way to please eachother in every type of intimacy. Its just always great and we make eachother better. we are not in a relationship bc we are scared what every one else will say. It will be such a bad look, everyone will hate us and have something to say. Am i wrong ? me and him both decided in a couple yrs if we feel like its not the best we would just rather be in eachothers lives as friends then nothing at all but its something we both very desire... 😔 i feel like it would be different if she didnt have to be in his life forever. But i was always told everything happens for a reason , me and DB had 3 major fights during our friendship maybe we weren't supposed to stay friends ?