Heavy wetter ....how do you know?

I have been boosting Ben's little lambs with a little lambs booster and every other nappy for that matter. The MEOS I am using the snap in liner either snapped in on bigger size, or unsnapped on smaller size.

He has never out weed a nappy though I think, but then he is also weird and wees to the back - it seems to always end up wet at the back