In the USA, with the laws the way they are, we do have to be careful. A 22 year old dating a 17 year old can be charged with "statutory rape" if the younger person's parents or guardians object.
In the UK, the age of majority is 16, yes?
Unfortunately, I know a guy who went to prison for this. The teen involved told the guy that he was 18. [There was a drunken party involved too] The teen begged the guy and the guy believed that the teen was 18.
The teen turned out to be 16 and guy went to prison. Oh, and the guy had a Public Defender. [In the USA, a PD is a lawyer that the court provides to people who cannot pay for one. Some PDs are good and others not so much.
Do I personally see,
anything wrong with a 22 year old dating a 16 year old? No.
I was 17 and dated a 29 year old who was extremely respectful of me.
The exception to this are teachers, doctors, shrinks, counselors, and other professional helpers. They ought to keep their hands off the young people that they have a professional relationship with [and wait at least two years after termination of it]. And they should suffer severe legal consequences if they abuse the power of their unequal relationship in this manner.