(no relation!)

You are, of course, correct in that polygamous marriage in the UK is not legal, nontheless, the validity of marriages contracted elsewhere is not questioned, nor have I heard anyone talking about polygamous marriages in the same way as gay marriage. As I never read the Daily Mail I have no idea what it says.

I'm unsure of the position of someone marrying abroad anbd then coming to the UK when one or both partners are under the UK age of consent.

All this actually shows is that there is very little consensus on what marriage is and who can contract a legal marriage.

Which certainly brings into question the right of one group to impose their will on a multicultural society.