The US and the UK have several joint defense agreements. Their armed forces are integrated on many levels and officers are swapped for training. They buy and develop weapons systems together. They share a common language, a common culture, a common system of laws and a common system of government. Investment, money and people flow back and forth virtually unfettered.
Moreover, they are founding members of the five eyes. They share intelligence collection and distribution. Given these facts and the ability of the Brits to move freely in the US, what "secrets" would the UK be looking for? Military secrets? Economic secrets? Political secrets? Do you think a "bug" in the oval office would give them more insight into BHO's thought patterns than simply reading the newspapers and talking to other US political leaders? Why would they waste the resources?
Beyond that, there is the tacit five eyes agreement. Have you heard any official complaint from the UK or Canada about US spying? You won't. There is a reason for that.
Your right. At my company, there is a lot of UK engineers here working on a common missile compartment. We send a lot engineers to the UK for the same thing.