Why not your right testicle? Or both of your testicles? Does the left one work only? xD
No, even if you were a Saudi, my answer would be the same. xD
Because obviously, world powers do not like Middle Eastern countries going nuclear, even if Iran somehow manages to do it. They can impose sanctions on both Saudi Arabia and the Emirates. Saudi Arabia holds strategic weight in the region because it is the birthplace of Islam and they control Islamic sites and they are an energy super power. The Emirates is a multi-national country where locals are already the minority in some places like Dubai and if the US decides to impose sanctions on the Emirates over its nuclear program, the country will collapse immediately when foreigners leave the country. Saudi Arabia won't collapse under pressure, the UAE will. Therefore, the Emirates will never go nuclear unless these nukes are completely under the control of the Americans and the UAE rulership has no say in it. And in that case, you can't really claim you have nukes. Right?
Iran's foreign affairs is an issue on its own, but I wouldn't bet on the Emirates for the reasons I mentioned just recently. I have nothing against them, I'm just stating facts.