There is an upcoming social event organized by my employer where friends and family will be invited.
The company is a fairly small company in the UK and I will inevitably need to introduce my family to my boss, the CTO, who is immediately below the managing director.
I'm not sure whether to introduce him as "Simon, my boss", which seems to have all the negative associations with the word "boss" and will start the interaction on a bad note, "Simon, the CTO of Acme Ltd", which sounds a bit dry and too formal, or just "Simon, another colleague of mine", which might irritate him since it ignores his well earned professional position, especially coming from an arrogant graduate.
We are on friendly terms and regularly talk about our personal lives, so I don't want to be too formal while at the same time not be too informal and disrespectful.
And of course, the culture in the UK may be different to that of elsewhere, although other perspectives would be useful.