Sean Stewart to Brandi Glanville -- You're Pathetic!

Adrienne Maloof's new BF Sean Stewart doesn't have time to deal with "Real Housewives" drama spewing from Brandi Glanville's mouth ... telling TMZ, she needs to stop being so desperate for attention.

Sean was out in L.A. Friday -- when we asked him about Brandi blasting his relationship with Maloof on a TV talk show this week, where she said the couple's 19-year-age difference "makes me want to throw up in my mouth a little and swallow it."

Sean fired back with some choice words for Brandi and then left her with one last piece of advice.