Knock her up

You pound in and out of Veronica's pussy, knowing that you are just on the edge of cumming. Finally, Veronica moans as she orgasms, which is all you need to push you over the edge. There is very little cum, but there is still always the chance that you knocked her up.
"Very good," Ms. Young intones, "of course the chances of a female becoming pregnant after a male has exhausted himself, are very slim, but it's still a possibility."
One of the girls in the class raises her hand, "Ms. Young, the demonstrations we've seen are only from penetration in the vagina. Is it possible for a woman to get pregnant through oral or anal sex, and if so, would it be possible for a man to become pregnant as well?"
Ms. Young looks at the girl, "A very good question. I will tell you right now that oral sex won't work, but as for anal a practical demonstration would probably be best to show the results. John, could you come up here."
You look to see that John is sitting at the back of the classroom, a guy who you never liked.
Ms. Young turns to you and says "Since we already have one male subject up here, we will start by testing to see if the male of the human species can get impregnated."
"Ms. Young," you complain, "I don't think I can perform anymore"
"Nonsense," she replies, "all you have to do is lay down and let John do the work."
You look at her in horror, but it is nothing compared to the horror you feel when you realize that for some reason, you can't retreat from the scenario. You try to escape, but are easily overpowered by Ms. Young and John.
"Notice class, how the receiving male subject tries to resist anal sex. This is common, as it can be painful when not accepted by the male on the receiving end."
Ms. Young folds you over the desk, as John, already hard, positions his cock behind you.
"While we're at it," Ms. Young states, still calm, "this will be a good time to also demonstrate what can happen during intercourse if insufficient lubrication is used."
You try one last time to retreat from the scenario, but you are still trapped, as you feel the tip of John's cock on your buttocks.