Fucking a pregnant woman -- who's not your wife, of course -- is one of the hottest experiences. The hormones make them so horny, and you can cum in her cunt with no worries.
During my wife's two pregnancies, one of the benefits for me was how horny she got. And that's when her boobs got so much bigger. Those were some of the hottest sex of our marriage. And this babe is one hot prego!