Boobs, blunders, clangers – whatever you call them, Romney likes to drop them. And he's really outdone himself in London

From criticising the biggest sporting event Britain has held in over 40 years, to "looking out of the backside of 10 Downing Street", Mitt Romney's first foreign trip of his presidential candidacy hasn't gone quite as well as he might have hoped. As the former Massachusetts governor continues to gaffe his way across London, here's a round-up of Romney's red-facers. So far.

On the Olympics: 'There are a few things that are disconcerting'

On Wednesday, the day he arrived in London, Romney was interviewed by NBC's Brian Williams. In a softball warm-up question, Williams asked Romney about his wife's horse, Rafalca, which will be in competition in the dressage, and whether Britain looked ready to host the Olympics. Easy, surely? Not for Romney.

"There are a few things that were disconcerting," Romney said of the event which has been 15 years in the planning and is expected to cost over £9bn.

"The stories about the private security firm not having enough people, the supposed strike of the immigration and customs officials – that obviously is not something which is encouraging."

It put a bit of a dampener on Romney's meeting with David Cameron on Thursday. "We are holding an Olympic Games in one of the busiest, most active, bustling cities anywhere in the world," the prime minister said, pointedly. "Of course it's easier if you hold an Olympic Games in the middle of nowhere." (Romney ran the 2002 Winter Olympics in Salt Lake Ciy, Utah.)

Red-face rating: 8/10. Take that, Romney! Now get that horse out of my sight.

On Ed Miliband: 'Mr Leader'

On to a meeting with the leader of the opposition Labour party, Ed Miliband – a man often criticised for being awkward and lacking a common touch. They should have got on famously. But Romney seemed to forget Miliband's name. "Like you, Mr Leader, I look forward to our conversations this morning," Romney said.

But he reeled it right back in, British-style, with some spontaneous patter about the weather. ("Could not be better. Fortunately the sunshine is out. The warmth is here.") And Miliband's team smoothed it over, recognising that American politicians often refer to each other by their titles.

Red-face rating: 3/10. You're not in North Korea now, mate.

On meeting the leader of MI6: 'Appreciating insights'

And another Mitt Romney blunder: confirmed outside No 10 he met head of MI6. Aspiring US presidents not meant to say that — Nicholas Watt (@nicholaswatt) July 26, 2012

The existence of MI6, the international arm of the British secret service, was not officially acknowledged until 1994, 82 years after it was established. But the organisation is still shrouded in secrecy, and its operations – and the diary schedule of its chief – are rarely acknowledged. But here comes Romney, in fully open mode: "I appreciated the insights and perspectives of the leaders of the government here and the opposition here as well as the head of MI6".

Got any pics, Mitt?

Red-face rating: 5/10. "Area 51? Yeah, I went. Saw a load of aliens there. What of it?"

At Downing Street: 'Looking out through No 10's backside'

Mitt Romney at No 10 on 26 July 2012. Photograph: Paul Cunningham/Corbis

There are two things you should know before you "look out of the backside of 10 Downing Street", as Mitt Romney did on Thursday.

Firstly, in Britain, "backside" means "ass". As in the part of the body. Secondly, "10 Downing Street" is often used in political reporting as a synonym for a press spokesman for the prime minister, in the same way as "the White House" can say things or have opinions.

Red-face rating: 2/10. A minor linguistic misunderstanding.

On the special relationship: 'Our Anglo-Saxon heritage'

Strictly speaking, this one isn't Romney's fault, but still, the media loves a narrative, and this comment certainly plays into it. Before the trip had even begun, a Romney "adviser" was quoted as saying the Republican contender would be better placed than Barack Obama to sustain the transatlantic relationship with the UK because of a shared "Anglo-Saxon heritage.

The racially-tinged remarks prompted outrage, and cued a stinging attack from vice-president Joe Biden. Andrea Saul, the senior Romney spokeswoman, attempted to row back but the damage was done.

Red-face rating: 8/10. What a way to begin.

A final indignity: bashed by Boris

The London mayor, Boris Johnson, is not unfamiliar with foot-in-mouth syndrome. So it must have been particularly humiliating to be taunted by Johnson, speaking to a crowd of thousands at an Olympic torch ceremony in Hyde Park.

The Geiger counter of Olympo-mania is going to go zoink! off the scale! People are coming from around the world, and they're seeing us, and they're seeing the greatest country on Earth, aren't they? There are some people who are coming from around the world who don't yet know about all the preparations we've done to get London ready in the last seven years. I hear there's a guy called Mitt Romney who wants to know whether we're ready. Are we ready?

Red-face rating: 10/10. Time to go home?