Hello I am a 28 male. I have been running 15-20 miles a week. They other day I ran 5 miles at a person best time, i was drenched in sweat and tights were not fitting well. When i got home I did not take a shower for a while and masturbated. After masturbation i noticed some lumps on my testicles, it looks just like a stretched spot of my testicles. If you stretch the testicles out you can hardly tell. They do no hurt, itch, nor do i have discharge. I am wondering if this is because i stayed in my tights so long and were irritated when running. 

Any ideas what that can be?