Why does it burn when I ejaculate inside her?

== Go see a doctor. == If you are the one that is burning when you ejaculate in her while having unprotected sex you should really go have that checked as it could indicate that you may have an infection or an STD - she should also be tested. If it is burning as you are using a condom/lubricants/paints etc. it could be due to the spermicide/chemicals that you may be having a reaction to it - use condoms that have no lubricants/spermicides. If she is the one burning it could be and infection or an STD. You both need to have tests done where this is concerned and do not have sex anymore until you find out for sure what is going on as well if you need to be treated for anything you both must be treated and do not have any sex until after fully treated - then see how things go.