The song "Tan Lines" by JJ Lawhorn is about the joys of summertime and the attraction of girls with tan lines. The lyrics describe the excitement of seeing girls in bikinis on the river bank and the anticipation of seeing their tan lines. The singer admires the beauty of the girls and the way the sun kisses their skin, making him want to grin. The song celebrates the carefree and fun-loving nature of summertime, with references to jumping off boats and enjoying the long dog days. Overall, "Tan Lines" is an upbeat and lighthearted ode to the pleasures of summertime and the allure of tan lines.