Eye-cup, can you spell it?

Luca - Daddy?
Me - Yes Luca?
Luca - Eye-cup, can you spell it?
Me - eh? what do you mean eye-cup? Is there even such a word?
Luca - Eye-cup, can you spell it?
Me - (ha, I've been here before, got him this time though) Yes Luca, 'i' 't' - you said can you spell 'it' :-)
Luca - NO Daddy! Spell 'Eye-cup'!!!!
Me - (Hmmm, suspicious!) - Err, OK, 'e' 'y' 'e' '-' 'c' 'u' 'p'
Luca - NO! Daddy! Eye-cup as in iPhone, iPod, iMac, iPad!
Me - Ha, OK, iCup; 'i' 'c' 'u' 'p'
Luca - Hahahahahahahaha -  'i' 'c' 'u' 'p' - i see you pee, get it?!!!!! :-)
Me - Got me again Luca!

Apparently one of Max's, stolen by Luca - Nice one Max; rascals!
This all happened in adjacent showers after a swim yesterday so must've caused some hilarilty amongst the others in the changing rooms!