I do periodically have interactions of the sort, but usually only after knowing the person for a while and trusting them to the degree that I allow myself to be influenced by their attentions.
In the last three cases, it has led to them coming to me some months into the relationship and admitting there was someone else, and me telling them (in complete honesty) that I knew. Perhaps, if that weren't the pattern, I could more freely engage in such interactions.