Rick Ross -- 50 Cent is IRRELEVANT, He Doesn't Deserve A Response

50 Cent may have been hoping to start a blood feud when he publicly insinuated Rick Ross and Diddy were gay lovers ... but sources close to Ross say there will be NO reprisals.

Ross won't retaliate for one simple reason -- he doesn't give a crap about 50 Cent or anything he says -- he thinks 50 is IRRELEVANT. 
50 briefly posted a pic on Instagram Sunday showing Ross leaning in close to Diddy as if they're about to kiss ... with a caption that said, 'something ain't right' -- with the clear implication the rappers are gay.

We learnt that Rick plans to let it slide ... he wants to focus on making hit records ... and not on a childish beef with an old enemy.