I just started seeing this guy and we've been intimate. I've noticed that he has whitish ridged lines around his waist, just above his butt cheeks. On both sides of his body. They kind of look like scars or maybe even scarification. But there's no pattern. We really don't know each other that well so I'm not going to ask him. Not yet. I just want to know if it's possible these could be stretch marks (they look almost like welts but not all red) or if he's into something weird.
Stretch marks are more common in women than in men. Some men are more susceptible to stretch marks than other men and this condition could have been caused by rapid growth in their adolescent years, weight gain and then weight loss, or some other medical condition. Assuming they are stretch marks, and not the result of some outlandish behavior, then he could consult with a few dermatologists about the prescriptive treatment options that are currently available. Assuming it's a cause of concern, there are a few other options, although pricier, such as laser treatments and dermabrasion. Best to consult with a board-certified dermatologist or plastic surgeon on alternatives to treat stretch marks.
Hopefully there is nothing weird about the person you've been with and his stretch marks were caused by growth spurts, gaining muscle mass by working out or gaining and then losing weight. These irregular-shaped, discolored markings come in the form of stripes or lines. Some are lighter in color, some are darker. Stretch marks could also be the result of a health condition that caused an overproduction of corticosteroid in the body. This overproduction of corticosteroid can reduce the amount of collagen production, limiting skin elasticity.
If you are concerned about your partner's stretch marks, perhaps a frank discussion and discretely suggesting a few solutions to the issue may help. There are some less invasive treatment options to limit unsightly stretch marks, such as tretinoin creams, but best to consult with an experienced dermatologist to find the best solution.