LeBron James -- I'm Cool With My Mom's ... 32-Year-old BF

LeBron James is 29. The guy dating his mother is 32 ... and apparently, the NBA star is totally cool with it.

In fact, LeBron posed for a pic with his mom's BF -- a rapper known as Da Real Lambo -- after the Cavs beat the Atlanta Hawks on Saturday.

Lambo has reportedly been dating Gloria James for about a year ... and he's already referring to her as his "wifey" on Instagram.

Clearly, Lambo loves the lifestyle ... posting pics in private jets, boats and expensive-looking resorts ... but it appears LeBron doesn't have a problem with it.