Three possibilities:
Condoms
Lube
STD
I would thing that two people having a latex sensitivity develop that at the same time to be astronomically rare.
Same applies to using KY.
Since both of you were ok until relatively recently, I think we can rule out allergic reaction there.
Unless you got a bad batch of condoms/KY -
There has been a KY recall:
http://www.huffingtonpost.com/tag/ky-recall/
"
The recalled brands are K-Y Tingling Jelly, K-Y Sensitive Jelly and K-Y Silk-E Vaginal Moisturizer and Personal Lubricant.
McNeil said Friday that all three are safe and there are no "product performance issues," so consumers can keep using any they have left."
And the Other article deals with vagina - so unless your vagina's are hurting....
So by a process of elimination we are left with one possibility, which given how both of you are affected in this manner, and how far more likely it is for two people to share in a contagious disease.... Chances are rather high you both have an STD.
The two most common STDS that Gonorrhea and Chlamydia:
"
Gonorrhea can cause rectal pain, especially during a bowel movement. A sore throat can result from a gonorrhea throat infection." Source: [URL="http://kidshealth.org/parent/infections/bacterial_viral/gonococcal.html"]click here
[/URL]
"
Gonorrhea is treated with antibiotics. Because patients with gonorrhea frequently also have chlamydia, they are often treated presumptively for both diseases just on the basis of a single diagnosis (for more on chlamydia treatment click here.)" Source:
Click here
However this is not the only potential problem, there are other infectious diseases which can be passed from person to person that are not typically considered 'sexually transmitted diseases'.
Given that you are both are experiencing the same thing after a similar amount of time, I think that it would be most logical for you both to be seen by the same doctor.