RE: Syphilis Titer of 32

PLEASE HELP!!

Long story short! My male partner claims to have been faithful throughout our relationship of 6 years. Recently, he had a physical and was tested for Syphilis and his results came back positive. He was re-tested 7 days later and positive results were rendered the second time as well. I tested twice also and both times my results came back negative. My partner titer was (32) both times. The doctor gave him an order for G penicillin 2.4 million units IM injection for a single dose to eradicate the disease. Can anyone tell me if they think he had this disease and contracted it before we were in a relationship, (over 6 years ago)
or do you think the chosen treatment and titer results are more consistent with a more recent exposure perhaps between 1-14 month or anytime during our relationship. Your help is greatly appreciated! Thanks in advance:-)

BTW, asking this question for a friend.