HI. Thanks for your query and an elucidate history. The cause of pain in testicle::: -Epididymo-orchitis, since your partner has yellow vaginal discharge, you getting UTI and retro-grade infection is a great possibility. -Torsion, if inadequate and recurrent can cause the similar pains reducing and increasing as you described. -Varicocele can cause local and abdominal pain. I would advise you the following: Urine -routine, microscopy, culture and sensitivity before start of the antibiotic. Blood Ultrasonography and color doppler examination of the abdomen for genito-urinary system and scrotum Gynecologist s examination of your partner and ful course of antibiotic, metronidazole, anti-fungal for both of you. No sex till your both are cured. to use condom later on.