My adult child isn’t in touch often — should I expect them at my wedding?

Dear Eric: My 21-year-old child responds only sporadically to texts and phone calls, often going days or weeks without a response. They live across the country with their other parent during the summers and holidays.

When I get the chance to see them face to face, which is once a year if I am lucky, it is as if no time has passed and it has the same warm, loving feeling it always had.