Ask June: Clever in Cleveland

Dear June,
While my roommate was away for the weekend her betta fish died. Because I knew that she was very attached to the fish I went to the pet store and purchased a replacement that looks very similar to the dead fish and flushed the dead one away. My roommate is none the wiser. My boyfriend says that I should come clean and that my behavior has been patronizing and deceitful. I believe that I have spared her unnecessary pain. What do you think?
—Clever in Cleveland