If you find out your S/O has been having dinner and drinks once a month with a friend, would you consider that cheating?

I’m having a debate with a friend over this. If your S/O is going out on a regular basis, say once a month, with a friend and doesn’t tell you, would you consider this person is cheating, or at the very least, dishonest? Let’s say there really is nothing going on other than dinner and drinks. Do you think your S/O should tell you? I think by keeping it quiet, it makes it look like something is, or could be going on. If nothing is going on, why not tell the S/O?