I'm sure several persons have the same experience that I sometimes do when making a questionable or potentially comment-worthy purchase at a store. While I had reported on this phenomenon once with regard to too much levity regarding my purchasing a tube of Boudreaux's Butt Paste, I've noticed this with other purchases as well: buying K-Y Jelly, purchasing a lacy lavender thong while, unfortunately, being checked out by a grandfatherly man, a stuffed Domo-Kun doll, and others.
Why is this the case? I think it's because there's a tension between our Public Self and the side of oneself that we choose to keep private. Normally, many of us have been conditioned to keep different sides of our selves apart; and it's quite adaptive for this to be the case.
For example, knowledge that I might be wearing that lacy thong might serve as a distraction to students or co-workers, or that I bought a Domo-Kun doll for myself might betray a more juvenile side of myself that is inconvenient. Therefore, some purchases are best made from complete strangers!
This is true even for the diet-conscious. Maybe you would rather not be seen ordering an Awesome Blossom from The Outback if you claim to be on a diet.
On the other hand, no one is likely to form an opinion regarding a possible purchase of ear buds, artichokes, or kitty litter.
Years ago, William James wrote about the types of self: the social self, the actual or real self, and others. When there is some lack of congruence between the first two, this is often the result of some strategic impression management: presenting a façade for the consumption of others.
We all do it. For example, we might pretend to be more into sports than is really the case. (I suspect guys may feel this pressure more!) But with consumable goods, some can fall into the questionable area. (Are you comfortable being seen leaving a sex toy store, for example.) Therefore, the best approach is the conservative one: keep it hidden.
So how can people handle this?
One approach is to never purchase said items.
Another approach is to purchase them from venues outside of one's community. This is sometimes done by some ministers whose churches forbid alcohol. At least it keeps them from casual gossip.
But another one, harder to pull off, is to not give a darn about the impression one might be projecting.
But the one usually followed is to make those anxiety-provoking purchases and hope you encounter no one that you know.
And possibly worry about one of your students imagine his teaching assistant wearing a lavender thong!
But, maybe, Sgt. Hulka from the movie Stripes gave the best advice on another topic; but which is generally applicable to other situations.