Heather Corinna replies:
I have always been wondering this question. I've been asking all of my friends about it, but I'm unsure of their answers. So I want a professional answer. So my question is: when wearing a condom, do you HAVE to pull out before or when you "erupt", or can you just keep going?
Condoms are designed and tested -- each and every one of them, by every manufacturer -- to be able to withstand ejaculation (what you're calling "erupting") as well as to contain a single ejaculation: the amount of semen a man emits when he ejaculates. They test them by blowing amounts of air into each condom with a level of force (called "airburst tests") far greater than the kind of force which occurs when a man ejaculates.
If you look at a condom, you'll see that at the end of it, it's shaped a little bit differently than the rest, with a tip that kind of looks like a long nipple. That "reservoir tip" you'll often see mentioned on condom boxes and in their instructions is the part of the condom built specifically to hold ejaculate (or "cum").
When you put a condom on, so long as you do so properly, leaving that tip hanging off the end of your penis, and pinching it to remove any air bubbles, it's totally fine to ejaculate while you are inside a partner's vagina, anus or mouth. Just be sure you're also doing other things that help condoms stay intact, like using extra lubricant with your condom, using good quality condoms that aren't past their expiration date and storing your condoms in a place where they'll not get overheated, frozen, or beat up by being carried around too much.
That isn't to say that a person can't withdraw with condom use if they are more comfortable with that.
Just know that it can actually make your condoms LESS effective to do so if you do not remember to hold the base of the condom when you withdraw.
Holding the base of the condom as you pull your penis out of any orifice is important when using condoms whether you withdraw in advance of ejaculating or not, but it can sometimes be easier to space out holding the base when you're in the middle of orgasm or about to orgasm, since at that point in time, most of us have an understandably tough time thinking clearly. It also, obviously, can be a bit of a bummer to have to pull out right when you're feeling so great, so if you or a partner aren't feeling like condoms alone offer you enough security, you might want to look into a secondary method of birth control to use that doesn't require doing anything during orgasm, like adding a spermicide, cervical barrier or a hormonal method of contraception (if pregnancy is your concern), like the birth control pill or the vaginal ring.
For more on proper condom use and how to buy condoms, take a look at Condom Basics: A User's Manual, Condoms, and Your Map to the Condom Aisle. For ideas about what methods are best to combine with condoms for couples who want greater protection against pregnancy, see The Buddy System: Effectiveness Rates for Backing Up Your Birth Control With a Second Method, and if you want to get a better idea of all our options with contraception, you can check out Birth Control Bingo!