My dog likes to smell and eventually lick our other dog's urine until he begins to slobber and salivate. How do I correct this behavior and what is the cause of it?

I purchased our dog from Lynx you in 2005 and I'm wondering if you can help me solve a problem I started to have with him. My girlfriend adopted a lab from the animal shelter and they get along great, but when the lab urinates Lynx has to run over smell and eventually lick the lab's urine until Lynx begins to slobber and salivate severely. How do I correct this behavior, and what is the cause of the behavior? Thanks.