No, this move is highly illegal, dangerous, and legally impossible under both US and UK laws.

An arrangement where a 17-year-old vulnerable minor moves internationally to live with an unrelated 25-year-old adult triggers severe legal restrictions, immigration blocks, and immediate child protection interventions.

1. Legal Status of the 17-Year-Old (Minority)

In both the US and the UK, a 17-year-old is legally a minor. Because the minor is classified as vulnerable and autistic, they cannot legally consent to relocate internationally or choose their own living arrangements against parental or state guardianship.
• Moving a minor out of the US without the explicit, documented legal consent of both parents or legal guardians is treated as international child abduction or custodial interference.
• If the minor attempts to run away to the UK, law enforcement and child protective services in the US will step in to return them home.

2. Strict UK Visa and Immigration Barrier

A US citizen cannot simply move to the UK to live there permanently; they must qualify for a valid long-term visa.
• No Visa Route Exists: There is no visa category in the UK that allows an unrelated 25-year-old man to sponsor a 17-year-old minor to come and live with him.
• Border Control Intervention: If a 17-year-old minor attempts to enter the UK alone or is met by an unrelated adult, UK Border Force will immediately detain the minor at the border. Under Section 55 of the Borders, Citizenship and Immigration Act, border officers are legally mandated to investigate the relationship to prevent grooming, trafficking, and exploitation.

3. Immediate Child Protection & Criminal Investigation