Spit or Swallow?
Does G!d want me to Spit or to Swallow?
First thing's first, is oral okay?
Short Answer: Yes!
Longer Answer: The general view is that a couple may do as they wish provided it's all consensual.
This doesn't fall into the category of "שפיכת זרע" (sh’chatat zerah - spilling of seed) but rather the seprate category of "ביאה דרך איברים" (biyah derech ivrim - penetration by way of the limbs).
This is because it increased marital pleasure!
But oral is only halachically sound within the exclusive framework of a Torah-permitted marital relationship and strictly during the time that a woman is not in her niddah state.
So if oral is okay, can I swallow?
The Rabbis discuss almost everything, but swallowing ejaculate didn't make the list! This is probably because of the Halachic bias against homosexuality. The Rabbis, as men, wouldn't admit to being confronted with the issue to spit or swallow, because doing so would imply they were engaging in homosexual acts.
Because it isn't discussed, the question is the kashrut status of semen. We can discuss that based on another type of human secretion that they did talk about- breast milk.
Is Breastmilk Kosher?
Ketubot 60a
Breastmilk is permitted when it has been removed from the woman’s body. Fundamentally, human milk is a permitted substance. However, it is prohibited for anyone other than a very young child to nurse directly from a woman’s breasts, and one who does so is considered like one who consumes milk from a non-kosher animal.
תָּנוּ רַבָּנַן: יוֹנֵק תִּינוֹק וְהוֹלֵךְ עַד עֶשְׂרִים וְאַרְבָּעָה חֹדֶשׁ, מִכָּאן וְאֵילָךְ — כְּיוֹנֵק שֶׁקֶץ, דִּבְרֵי רַבִּי אֱלִיעֶזֶר. רַבִּי יְהוֹשֻׁעַ אוֹמֵר: אֲפִילּוּ אַרְבַּע וְחָמֵשׁ שָׁנִים... פֵּירַשׁ לְאַחַר עֶשְׂרִים וְאַרְבָּעָה חֹדֶשׁ וְחָזַר — כְּיוֹנֵק שֶׁקֶץ. וְאָמַר רַב שֵׁשֶׁת: אֲפִילּוּ מִצְוַת פְּרִישָׁה אֵין בּוֹ. לָא קַשְׁיָא: הָא דְּפָרֵישׁ, הָא דְּלָא פָּרֵישׁ.
So... cum is Kosher as long as you don't "drink it from the body"?
That's a valid way to read this source, but I actually think there's more to it in the case or human semen.
The additional layer comes in when we consider the Jewish value of פקוח נפש (Pikuach Nefesh - preserving a life).
According to this principle, Jews are actually required to break a Jewish law if breaking that law will "save a life."
What does health have to do with spitting or swallowing?
It's all about the risk of sharing Sexually Transmitted Infections (STIs). If you're having oral sex without a condom or other barrier method, there is a risk of transmitting STIs because there will be a mix of bodily fluids (semen, saliva, and blood - through normal microtears in your cheeks and gums).
Swallowing immediately after someone ejaculates into your mouth reduces the risk of you contracting an STI, because it means that you are reducing the amount of time that cum sits in your mouth.
Does G!d want me to Spit or Swallow?
It's up to you!
As with all sex acts, what's most important is that you're doing what's right for you and your partner or partners.
It's crucial to make sure you and your partner(s) are on the same page before starting your sexy times, and that everyone is going into the experience with informed consent!
Sources
en.wikipedia.org/wiki/Fellatio_in_Halacha
sefaria.org
jewfaq.org/kosher_sex
jewrotica.org/2019/02/jews-and-sex-toys-what-is-allowed
Jewish Intimacy and Vulnerability Week 2
cdc.gov/std/healthcomm/stdfact-stdriskandoralsex