A surprise visitor

The two siblings just barely had enough time to get some clothes on before their new visitor was due to arrive.

Adam had managed to get his jumpsuit back on while Cindi got her tiny bikini on and was able to wrap a short silk robe around herself for at least some modesty.

Her platform heels still echoed down the corridor with every step she took and Adam was looking forward to quickly getting rid of these unannounced visitors so that he could get back to exploring Cindi's sweet body again.

"Do you have any idea who it could be?" Cindi asked her brother as they approached the airlock just as the new ship started to dock.

"No. I have no idea." Adam answered, "The ship's ID badge is set to 'Anonymous' so we can't see who's on it."

Adam glanced over towards his little sister and suddenly wished that she was wearing something a little less revealing as they prepared to greet their surprise visitors.

Who/what docks?