Boys swimming shorts with cupcake/ice cream pattern, fully lined with an elasticated drawstring waist. Matching girls swimsuits with the same pattern also available.
 
These do come up a little small. Measurements of the actual swim shorts:
2 Years: across the waist 23cm, length 28cm
4 Years: across the waist 25cm, length 30cm
6 Years: across the waist 27cm, length 32cm
8 Years: across the waist 29cm, length 34cm