Hello
I really appreciate your concern
There is no test which can directly tell you who is responsible
nobody can be blamed on either way
This can be caused by number of reasons like
dryness of vagina or deficiency of lubricantions, infection or inflammation of the penis
If you can provide me more details like his medical history like if he is having
diabetes or
liver disease
Similar complaints in past, I will be able to guide you better.
If I were his treating doctor, I would have advised him to keep it clean and apply antiseptic ointment
if it doesn't improve or worsens than I would have ordered few investigations like blood for
hemoglobin, CBC Liver and
kidney function test, blood sugar and urine culture or an
ultrasound if need be.
He may require a course elf antibiotics under supervision of doctor.
Thanks for your question
Wish you both good health