Quote Originally Posted by scottish-guy View Post
That would be the answer - except that he is specifically not allowed to get married or enter a civil partnership in the UK on a Visitor's Visa, nor does Vietnam recognise same sex marriage, so that's out too.
If you are happy with the idea of marriage*, then would it not be possible to identify a third country, where you can get married & where the marriage is likely to be recognised in the UK ? Must be a soft target in the Shengen zone ?

(*I would not entertain the idea myself, but that's not relevant to this thread)