I love having sex with pregnant women. Only done it a couple times. As a donor I'm only needed to make it happen in the first place usually and move on to the next recipient once they are preggers.
This scenario makes you wonder if grandpa might be the father of the baby in this girl's womb. Unprotected sex at this point won't get get any more pregnant than she already is so grandpa can cum in her all he wants, However, I'm still a little suspicious about the real sperm donor because the girl seems to be familiar with him and she did say that she enjoyed the vaginal insemination