Well now the truth is out, eh?
When we packed his rucksack for the return jouney, I thought I heard some murmering about getting some cheap cigars on the ferry, but dismissed it out of hand.
Now that he's sat on the worktop in the kitchen, awaiting his next trip, I did happen to mention to the boys that he seemed to have an exceptionally silly grin on his face!
I have questioned him about his behaviour, but his lips are sealed!! Although it is possible hear a faint mumbling of something to do with "A brother!!!" and "It wasn't me!!". Means nothing to me.