Question: After my partner ejaculates I experience a burning sensation in my vagina. Can you tell me why this is?
Answer: It is possible for women to be allergic to the proteins contained in semen. An estimated 5% of women experience this. If you do not experience this burning when a condom is used, then this is a possible cause, as long as you are not also allergic to the material the condom is made of, many people are allergic to latex.
Here are some links to additional information on semen allergy.
http://www.diagnose-me.com/cond/C606187.html
http://allergies.about.com/cs/intimate/a/aa121800a.htm
http://www.medication-now.com/allergies/semen-allergy.htm
Here are some links to additional information on latex allergy.