Breaststroke: butterfly-legs before or after expell.-phase?

Hello everybody, Recently I´ve heard about adding the butterfly-legs to the breaststroke. At this moment I´m training on technique. And now I´ve this question: The butterfly-legs-movement does it have to be before or after the expelling phase? At this moment I do: 1) arms-movement 2) breaststroke-legs 3) expelling phase (*), strectching the body for 1 to 2 seconds 4) 1x butterfly-legs (*) Hope this is the right English expression. Goal is not competition swimming. But making my breaststroke more active; give it more speed. Allready thanks for the answers. ;-)