this is a tuff question. Because while it is humiliating in both cases of cumming in my mouth or me having to clean it out of her. It all depends on how she talks to me when it is happening. In all cases it is so good to hear her talking to me about eating, tasting and swallowing his cum.
I can't understand how humiliating or embarrassing a spouse might encourage harmony in the relationship. However, you didn't put up enough options ... I've always felt it a woman's choice where her lovers put their cum, but personally I believe it should go where it was meant to go, in that tight, warm, wet pussy. As far as my reason for that, I can say most emphatically that it isn't so I can eat that cum out of her. But, fucking a well-used pussy is an extra-ordinary sensation in itself.