Why Does My Vagina Burn And Itch After Being Intimate With Someone?

I have not been sexually active for more than 8 months and then 1 week ago I had sex and afterwards it began to burn and itch. Today I noticed that when I pee and wipe there is what looks like brown dead skin cells on the tissue. He used a condom. But going back 8 months ago the last time I was sexually intimate with someone the same thing happened. I burned and itched for about 4 or 5 days. A condom was used at that time also. Both times the condom never came off or broke. What could it be.