Kinky or Vanilla?

So, Red and I had house guests this past week, who just left this morning to return home. Our guests were a man who has been one of Red's best friends for about twenty years now (whom I will call "A."), and his wife (whom I will call "M.").

As far as we know, this couple is entirely vanilla, so before they arrived I carefully made sure that our toys were all put away and out of sight. After having spent the past week with these people, Red and I are left wondering whether our discretion was really necessary.

On separate occasions over the course of the week, Red and I each witnessed A. deliver a playful spanking to M. When I witnessed it, M., who is much smaller than A., was climbing onto A.'s lap. He was sitting in our recliner chair, and she is tiny, so it took a little effort on her part to do this. Before she could sit down, A. wrapped his arm around her, pulled her OTK (well, OTL, really) and delivered several firm (but not really hard) swats to her bottom. She wiggled and whined, and he let her up. And that was that.

Apparently Red witnessed a similar event later in the week, as well as being a part of an interesting exchange in a local store. Red took them both to a local Walmart-type store to do some shopping. As they were walking through the kitchen section, A. apparently pulled a spatula down from the display.

"Do you know how I know this is a good spatula?" A. asked Red.

"No... how?" Red asked.

A. slapped the spatula hard against his hand. M. jumped and again protested. A. laughed and put the spatula away.

Things like this, along with some other general toppiness that occurred, has both Red and I wondering if these people are spankos (or at least the guy, anyway).

So, what do you all think? What clues do you look for to tell whether someone is kinky or vanilla?