Ill have my hubby do this whenever we cuckold roleplay. Once he cums in me I'll shove his head down there.
Whenever we started roleplay this, he would mention eating the other guys cm from me. I thought it was just spicy talk or his horny brain talking.
I asked him once while running errands if that really turned him on or if it was just part of the bedroom talk, he assured me it did. So I decided to test him. After a fun filled night of me dirty talking about ...... with another man he shot a huge load. He hadnt came in almost two weeks. So he had a big load. I kissed him and said "clean me". He hesitated for a split second and I shot him the "do as your told look" and he went down on me and it felt soooo damn good . I ended up using my toy a few more times.
Now if we are doing the naughty roleplay talk he usually always cleans me up.