Was chatting to MIL and I was telling her that ds2 (age 5) did 6 lengths (60 metres) on his back when I took him swimming yesterday.
Her reply? "He must get that from his dad - he was a very strong swimmer"
So nothing to do with the fact that I have been taking him swimming every week (sometimes twice) for years. And in that whole time dh has come with us once. I won't even mention that i happen to be a good swimmer and used to swim for the school 