Hi. Thanks for your query. Read and understood your problems. You were with your girlfriend and after 3 hours after she left you started pain in right testicle. After 10 minutes you noticed ache in the tube also along with swelling which went down after 2 hours. But it is still bigger and aching sometimes. Today you have right testicle pain and lower back ache. This indicate one of hte following reasons: - Partial torsion of the right testicle. - Acute infection This can be diagnosed by clinical evaluation, actual physical examination and ultrasonography with color doppler examination. The treatment will depend upon the findings and diagnosis; and will be urgent if there is a torsion.