chicken what about a Young Driver session if you have those near you? My DS is desperate to drive and has had a few lessons at Brooklands since he was 13 (Xmas pressies from granddad)
City break to European city?
Visit to Shard/other skyscraper?
Ticket to Comicon or similar?
Escape rooms - needs others to join in however?
One day cooking course - something tricky like sushi/pastry/dim sum/cake?
Laptop for college?
DS's birthday is early January so I have taken him on a European city break ever year since he was 12, quite cheap in January! Paris, Madrid, Rome, Nice, Marseilles. Lots of art galleries, markets, nice food, and a bit of biking, and all the free stuff available
and people-watching from cafés