I met a tourist from MExico while here in the U.S. We have been dating now for like 2 years. He comes and goes with a tourist ViSA.
I want to know what are the repercussions if I were to marry him while he is visiting the US on a tourist VISA.
He should be comign back in December and I don't want to let him go anymore.
Can I file papers for him to stay in the US once we are married?

If you marry, you can petition for him here in the US. Please note, that he should not have the intention to marry and immigrate if he is entering the US on a visitor visa.