It's difficult to hear the conversation from time to time, but he 'sounds' to me like the type of guy that has a lot of little fantasies, and asks his wife/mistress/hooker to indulge them. As she has a kind of Eastern-European accent, I just think she's a hooker.
One clear 'wish' is 1'36", where he asks her to sit on his face. On 2'15" she tells him to lay down, and says something like "I'm all wet"...
From than on, he's clearly licking her, and you can hear her moan softly and suck in air not so softly
On 4'33" he's saying something in the style of "I'm gonna take you in the ass as well", but she seems a little reluctant for such modus operandi
Anyway, the strange thing is that afterwards, nothing happened anymore. Was he disappointed? Don't know, maybe