In which case your dad would be breaking the law. Have you tried this on airsofters.co.uk??
Um nope? Wait... So I can play airsoft... Just not own my own gun?
All I've found online is that I have to be 18 to buy one, although I can use one that has been brought for me with supervision of someone over 18 years of age.
So, aslong as it fires 6mm bb's, I should be fine.
Also, because it's two-toned I don't need a licence or equivilent to own it.