What Causes Itching And Foul Odor From Penis After Unprotected Intercourse?

I m a girl (monogamous). I had unprotected sex with my husband for the first time. It s been a month now but he still feels mild itching sensation and bad odour over his genital area since the next day. He thinks that I have an std. But I no complications. I am HIV negative too. What could be the problem? Please help. What std tests should I take to prove him wrong?