Lol it's really complicated...Basically sky slept with 3 men...One of them was her boyfriend, one of them was her boyfriend's brother and one was her art teacher. The scans revealed that the baby was too big to be her boyfriends as she slept with him first so it must be his brothers. But her boyfriend doesn't know sky slept with his brother and has therefore been misled by sky into thinking that the bub is his.
Sky knows the baby is not her boyfriend's, but her boyfriend's brothers and all is revealed in a really good episode which i've already seen lol, all hell breaks loose when sky's bf finds out the baby is really his brothers...