Middle name help? Both boy and girl suggestions. My husband and I have been throwing around baby names but do not know the sex of the baby yet. We hopefully find out in 4 weeks but want to get a head start on baby naming! 

For a girl's name we really like Lillian and we will likely shorten it to Lily for a nickname.

For a boy's name we like Sebastian and the nickname would be Bastian.

Things we are considering for the middle names: Both first names are three syllables and our last name is three syllables starting with an "S." We'd like to not have a super long full name so possibly shorter middle names? Please help! We are stuck.