I firmly believe it's a woman's choice where her lover cums. Ultimately, she has the most risk relating to pregnancy and STIs. e.g. the world is full of single mothers, because the ******* has chosen to run from his responsibilities.
However, my ex and I both felt a trusted lover coming inside her, was so erotic, the pleasure out weighed the risk. A big creampie is a very sexy thing.
To me, it symbolized my ex wife giving herself to another man, and me submitting to it. I felt truly cuckolded.
My ex used to tell me, she felt sexier when a hot bull came inside her. It made the sexual act feel more complete, and the creampie was tangible evidence that she got her lover off.
Then there is the power exchange between the wife and her cuckold, when they he engages in "cleaning her up." If the Bull is present to witness this, there is also a greater power exchange between he and the cuckold as well.
I get the most satisfaction when a Bull cums inside the woman I love. If it's what she wants, I fully support it.