There is something oddly juvenile about this position but nothing particularly juvenile about its enactment. The man and the woman lie down so their heads are at opposite sides and their buttocks are practically touching. The lovers then form arches with their legs so their feet are touching at the sole and they are holding their legs up with their knees. Being inside each other is not always easy with this position but that does not always have to be the main aim of sex. You can try other things while in this position or enjoy the foot wrestle that will ensure.