What age is it okay to start dating?

I'm a homo and had 3 gf's when I was a kid. One up until I was 7 until we moved away and she was devastated and the other until I was around 11. I then had another gf around 12 and she was the baddest girl in school who had to be taught in her own class and would beat me up sometimes. She asked me if I would marry her, because her mother said I could.