Under United States immigration law you can only file an immigrant visa petition on behalf of a spouse, child, parent or sibling. You cannot petition for a boyfriend no matter the length of the relationship. You would need to marry in order to petition for him to receive an immigrant visa. You could consider a prenuptial agreement to limit potential financial obligations. You can read more about family-based immigration at http://myattorneyusa.com/family-immigration.
Answered on Apr 25th, 2016 at 3:39 PM