Water balloons - they're fun, innit.
Two small boys, one sunny day, a packet of water balloons and a lot of laughter.
I often post things we've done to make bath time more fun - and FTI water balloons are also fun in the bath - and don't need to be full of cold water.
Added water balloon fun comes from:
Glowsticks (I love them)
Tag (wet tag)
'Egg and spoon' races with big serving spoons