Brief Answer:
Most probably just irritation

Detailed Answer:

Hi,

This does not seem like herpes as herpes is fluid filled bigger sores and occur with fever.

This is most probably either mild irritation or mild infection of urethra after sexual intercourse.
But to be more sure, please get a complete urine examination including culture and sensitivity. You can also get a blood STD test prescribed by your doctor to rule out herpes, HPV, syphilis, etc.

Hope it helps. Let me know if I can assist you further.
Dr Vaishalee

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