I've noticed a red area on my penis shaft below the glans on the right side. It appears a red to pink color(usually more red after masturbation). When stretched it looks like shiny red lines. It has been like that for a while now. There is no pain, or discomfort and the area does not seem dry(just red and shiny). It almost looks as if the skin is being over-stretched. After not masturbating for a couple days it becomes less red and more pink. 

Could this simply be bruising or irritation from overuse? I plan on taking a couple weeks off from masturbating to see if it gets better. I also put vaseline on the area to decrease friction with my underwear.