Okay kiddo, so once upon a time there was a big business deal between two countries, Saudi Arabia and the United Kingdom. They called it the Al-Yamamah arms deal.
Basically, Saudi Arabia wanted to buy some weapons from the UK to make its army stronger and better able to protect the country. The UK was happy to sell the weapons and make a lot of money in the process.
However, there were some problems with the deal. Some people thought that the UK was giving Saudi Arabia a better deal than it should have because it also included some secret things that made it not just about weapons. This made some people think that the UK was doing something sneaky.
Other people thought that the UK might have broken some rules that they're supposed to follow when selling weapons to other countries. This was because the deal was so secret that not even the UK government knew everything about it.
So basically, the Al-Yamamah arms deal was a big business deal between Saudi Arabia and the UK for weapons. It caused some controversy because some people thought the UK might have been doing something wrong or sneaky.