Can I keep secrets from my gf because I have a criminal past.
Why do you want to hide your past?
Some of the things I do might be illegal, but that's none of your business.
I hear you, but it is wrong to hide your past from your significant other. You should be able to trust one another, so you need to talk to her about it. Otherwise you will be lying and hiding things from her your whole life.
Maybe I like to keep some things secret.
Don't you think she could get in trouble if you ever get caught? She has the right to know the kind of lifestyle you are into before being in a serious relationship.