Liz Coleman. Join. (Lightspeed Magazine #16).
Online here, so read it!
A young man makes a (final) return to Earth and home. He’s been living on Mars, and has begun a process of change, embracing a three-way relationship with members of the alien race which has stopped off in our system en route to their moment of salvation at the centre of the galaxy.
He’s carrying a child from that relationship, a pupating larvae, in a symbiotical relationship, both physical and emotional. As with stories of this type it focusses on what is being left behind, but also what is being taken on, and it’s a good example of this kind of story, with a couple of neat touches, without really taking this kind of story on much further.