I am Mexican, my wife is not even British but EU national.

When we moved here it helped enormously that we were married. They allowed me in initially as a dependant person and then it took a while to process my application to be recognized as an EEA familiy member (which is what allowed me to wrok as I wished).

Keep in mind that the current government is intent on tightening immigration requirements in order to please the rabid xenophobic that read the Daily Mail and other such fine publications. It may very well be thatat in one year's time it is more difficult for him to come over. A marriage certificate would be extremely helpful.