I wouldn't mind a friend getting my wife pregnant. Or, becoming best friends with my wife's long term boyfriend, and him knocking her up! Actually, becoming best friends with my wife's boyfriend sounds hotter! And watching him impregnate her.
My wife fucked a guy one night with a monster bbc. She said he was so deep inside when he filled her she thought it went right in her cervix. After she came home and fed me all of his cum, I unloaded inside her too. Fast forward a month or two and she's pregnant. The due date ends up being that exact night. Luckily I learned size doesn't matter when getting a woman pregnant. While the amount of time between each time you cum makes a big difference. The greater the time between the higher the concentration of sperm. Good thing for me my wife didn't let me get off unless I was with her. We went a couple of weeks or more between the last time and the night I came inside her, and in the end I won out.