NFL's Melvin Ingram -- BEST COUSIN EVER ... $165K Jewelry Run For Family

You know what they say about the family that wears stupid expensive jewelry together -- one of them is probably in the NFL ... like Chargers star Melvin Ingram.

The linebacker now has his fam dripping in more than $165k worth of bling ... which he just hooked 'em up with after a run to Avianne Jewelers in NYC.

Owner Joe Avianne tells us Melvin "went crazy" ... buying 25 diamond chains (1.5 karats each) for his relatives -- yes, cousins too. They all got "YPC' pendants for helping him launch a new YPC (Young Paper Chasers) clothing line.

But of course a guy's gotta treat himself too -- Melvin copped a Presidential Rolex, plus a 45 karat gold chain with 7.5 karat diamond charm.

Melvin's about to have a bunch of "new" kin come out of the woodwork.