The option under 'Summon Miles' is 'Oliver', unlocked after you catch them using the milking machine on your ship. You can find Oliver at 'The Scar', and the scene on your ship that unlocks the sleeping scene takes place in the medbay!
In the previous reply, I mentioned that you have to catch him using the milking machine on your ship! Once you've seen that event, the option to invite him to your bed unlocks! :3
