You are right about it being a very private act.
That means a lot to both my husband and I, and my regular lover.
Jeff used to like to cuddle up to me as close as he could, or would be allowed, when a new man would cum in me for the first time - if he knew ahead of time. He would cuddle up, caress me, and whisper to me how much he loved me and try to get me to pay attention to him. It was his insecurity, anxiety, angst, and fear. He will get almost grief stricken when they cum. In the early years he would comfort himself on my tits, and then later he got more comfortable eating me out. Once he is used to a man, like my lover, he will do it while they watch and rest.