Chances are you did not feel nauseous because you swallowed too much semen. A very, very small percentage of people are actually allergic to semen, and there's really no way that someone could become sick from over-ingesting it. Even if you were to somehow swallow a pint of it (which is nearly impossible, because a man's ejaculate only contains about 1-2 teaspoons, and a pint is nearly 100 teaspoons), the worst side effect would most likely be heartburn. That's because semen is non-toxic and is processed by your body in the same way as food.
However, TeenHealthFX is very concerned about your situation. Any type of sex should be a meaningful activity between two consenting people in a relationship. It is neither something you should be forced into. Your friends should not be making you swallow everyone's semen. Not only is that disrespectful to you, but it puts you at risk for contracting and spreading sexually transmitted diseases (STDs).
THE BIGGEST AND MOST IMPORTANT CONCERN WITH ORAL SEX AND SWALLOWING EJACULATORY FLUIDS IS STDs. If any of these people has an STD, they are very likely to transmit it to your mouth. This is an effective route of transmission for many STDs, such as Herpes 1 and 2, Human Papillomavirus (HPV), Gonorrhea, Chlamydia and HIV/AIDS. Many times people who have STDs do not even know it, thereby increasing your risk of getting an STD. The only way to prevent getting an STD is to practice safer oral sex .
TeenHealthFX urges you to stop and think about why you are hanging out with this group of people and seriously consider the risks you are taking by being with them. Your friends should not be forcing you to swallow their semen and should understand why doing so is considered high risk behavior. If you need someone to talk to about how to change your situation, you can call the Atlantic Behavioral Health System, Access Center, to find a counselor at (888) 247.1400.