How can you know if a guy is serious in courting you?

you can know if a guy courting you is serious,IF he never regret any minute of he's life spent with you. even if you hurt him A LOT and you did a lot of mistakes in your life he would still accept you show you that no matter what happens he would never ever leave you. if he still want you back in his life even if you broke up with him LONG TIME ago..Ü