Sexual activity is not always a prerequisite to cause genital infections. Other common infection can occur when personal hygiene is compromised.
Since you mentioned you have a tight foreskin, there is a possibility that unwanted material like smegma
, soap, secretions from previous sexual encounters, etc., can get gradually accumulated. This collection can be nidus of infection.
Therefore I encourage you to consult a competent genitourinary physician. It can be treated completely without much difficulty. You may also discuss the option of circumcision
if foreskin is too tight and cause problems during sexual activity.
You will be alright soon. Do not be concerned.
I hope that I have cleared your doubts. Let me know if you need further clarifications.