When seeing a couple versus a man, do you tend to "tone it down" in order to take the wife's feelings into account? Is your mindset also different when seeing a couple?
That would really depend on the couple, i think.
I don't have much experience with this, but i think some couples may have more jealousy between them than others.
I tend to focus more on the wife/girlfriend. Partly because I like playing with other women and maybe also partly because I don't want any jealousy between the couple later on but first reason is more like 90%
Although it's hard if the wife/girlfriend is not into the whole 3P play and mainly does it because her husband/boyfriend likes to live the fantasy.