When I answer, I also add, "How about you?" and he never replies or texts any further.
Why does he do this?
Its usually in the morning or late at night, when he gets off of work.
He knows that I don't drive, so its not like he's trying to ask me to come over, based on whatever I text him back.
Back story: We've been sleeping together for around a month and a half, but recently, we haven't been at all, which is fine with me, because we always knew there would be an expiration date.
We've talked on the phone before, never exceeding an hour. He's not very smart and usually just talks about really surface things.