Graham, it’s not grammatically wrong, but is very formal. In this context ‘tu aimes’ is colloquial and ‘correct’. 

Learning when to use vous in formal contexts is important in French, but so is learning when to use ‘tu’ in other situations. 

Two friends, family members, partners etc in a discussion like this would not address each other ‘vous’ (excepting something done jokingly in obvious jest perhaps).