I agree, that kind of situations can encourage husbands to clean up wive's pussies.
In my case, the last time my husband cleaned me up, was precisely the last time my ex boyfriend visited us. My husband and me had been fucking in doggy but none of us could cum. My husband and me always had less sensitivity fucking in doggy, something that never happened to us with other positions like missionary or cowgirl.
Some hours before our fuck, my ex came at home and Rick asked him to fuck me in doggy. We went to our bedroom and there I sucked his black cock until it turned hard. So, while he took his clothes out, I put myself in four legs over the edge of our bed. My ex stayed standing, he came to me and penetrated my pussy by behind. We fucked in that way just for one minute, but I needed a harder rub, so I asked him to move up over me. He sat over my hips placing her feet over our bed and he held my shoulders with his hands. (it was a doggy variant that I'm not able to make with my husband due he's so heavy for me) He continued fucking me in doggy some seconds more and I finally could cum.
My husband felt a immense excitation, just watching how my ex made me cum, in the same position which he had not been able to make me cum some hours before. So, while I was resting over our bed, he put his head over my pussy and cleaned it up until the last drop.