At 18, Can I Legally Move Out In Mississippi?

It is legal. I would not recommend moving in with your boyfriend. If you think you have problems now, you will create more by living with a boyfriend... especially one that has children. He should be focused on rearing his children.. that is NOT your responsibility. AT ALL. You have your whole life ahead of you . Your future will be bleak if you do this.Find a roomie instead. Get an education, skills, training.. so that you can be self sufficient. The "feel good" of living with a boyfriend wears off rather quickly. Then, you will have another set of problems to deal with. Don't do it!