I think it the fact that a pregnant woman is by definition, someone who is sexual. Knowing that a man's seed is inside her and planted itself. That a part of her is forever marked.
I personally love the idea of fucking a married hotwife pregnant woman and constantly bathing her pussy with my cum. Her husband knowing that I, his wife's lover is constantly filling up her chamber with my load.
I also love the idea of getting a hotwife pregnant, and her husband knowing that my seed is inside her body. That my semen entered her, became part of her, and that a part of me now runs through her veins. That I've conquered her pussy while he is only a visitor. That even as he lays down with her at night, the baby kicks him, reminding him - "Another man owns this pussy. Another man put his seed inside your wife and made her his own." Even as he has sex with her, her husband would know that she smells, tastes, feels different. Because of me.
I love how breasts change throughout a pregnancy. Absolutely beautiful.
