People think my family dynamic is weird

So my mom and my dad are not together bir have they ever been together. Ever. Their are 3 of us kids. I'm the oldest and then there's my 15 year old brother and 10 year old brother(Also another 2 year old brother but we will get to that). When my mom was 32 she said she had a clock and she wasn't getting any younger and she wanted to have kids. She's been best friends with my dad for 23 years so they decide to have a baby together. They didn't have sex because they don't see each other that way. They just inseminated. My mom always said she wanted her kids to have the same dad so after my 10 year old brother, she got her tubes tied. My dad thought he wanted the same thing and was gonna get a vasectomy but ended up changing his mind. He met his now wife and they have a son, my youngest brother. My mom and my dad are still best friends. I feel like I had everything kids that have married parents have. Christmases together, thanksgiving together. Family pictures. Both were at our sports. And I knew my parents loved each other. Just not in that way. People always tell me my family dynamic is weird and constantly tell my mom and dad they did it wrong and you should only have kids with the person you love. My mom's reply is always "I do love him". Same as my dad's.♥️