My mother taught me two ironclad rules for when a relationship is over: First, when a man starts planning a future without you.

Second, when another woman appears at his side who understands him better than you do.

I looked at my boyfriend Ethan, who’d just landed an offer from a top aerospace company in 

Seattle, and at Nina, my best friend. Then, out of nowhere, I heard myself say: “So—in your plans, is there any room for me?”

The words hung in the air. The animated conversation between them died on the spot.

Nina’s face twisted with awkward sympathy.