Is husband a jerk or am I the jerk?

My husband who I am with out of convenience, not love, continuously complains about missing cups, tumblers, gles. They are not lost...my 22 year old son drinks water in his room downstairs and forgets to bring them back up immediately. I think this is silly...worried and arguing over a cup or gl which is in my son's room, not lost. I do not leave because my husband and I are like roommates and it works out. But he is constantly picking on my son. Some things I agree on, but should I scold my son for a cup left in his room? Isn't this a silly issue?