So I have a duo set up with 2 girls from the same agency and I am wondering: do I need to switch condoms when going from one to the other, or can I just alternate at will?

Yes you need to change condoms or request that the ladies wear female condoms. That is a good alternative. There is more information on this subject on the newbie board. Take a look.

Otherwise it defeats the whole purpose of a condom.

I would see guys attempting to do this quite often when I was involved in the swing lifestyle. I've never been able to understand why so many guys have a problem understanding that this not safe or acceptable behavior. Maybe it's because they are protected so that's all that really matters to them.

By not changing condoms between partners or going back and forth, you are exposing the females to any potential STD's or STI's that either might have.  

Would you want a lady to use a 'previously worn' condom on you??? Gross,right??!!?? ...well it's really about the same thing......

OMG  why is this even a serious question?  Safe sex is about Everyones safety NOT just yours.

I really think you knew the answer to that question.

That is not sanatary.

Yes, Yes, Yes, to double dipping with brown sauce! >

http://video.xnxx.com/video35628/Shyla_Stylez_gets_her_asshole_ripped

Have the ladies use the female condom and you can swap back and forth as long and as many times as you can handle.  Good luck and have fun.

Every woman has different flora. You would no more want to spread from one to the other than you would bareback.

You didn't think about that very carefully did you? If the girls don't switch condoms you better run, run, run.

And, one thing more, gentleman, when you start using your fingers no double dipping without washing your hands again.

This stuff shouldn't have to be said but in the heat of the moment that little head seems to cut off all the blood supply to the big head and reason.

I can't tell you how many times someone wants to NOT use a condom when he's ready to partake of intercourse. Then I hear, "oh, you're safe right?" Of course I am but that has NOTHING to do with anything. How do I know that YOU are? If you're wanting to do that with me, how many others have you done it with, etc, etc, and how safe could they possibly be if they've done it with you? Be careful out there.

Just my two cents.
Anneke

GREAT answer!!