Tinie Tempah -- I'll NEVER Wear My $37,500 Marty McFly Shoes!

The British rapper who dropped $37,500 on the very first pair of those AWESOME "Back to the Future" shoes tells TMZ ... he NEVER, EVER plans to put 'em on his feet!!!!

22-year-old Tinie Tempah was leaving an MLB event in NY last night when he told us his prized Nike Air Mags are en route to Michael J. Fox -- who's gonna sign 'em!!!

As TMZ first reported, Tempeh outbid EVERYONE for the kicks at a charity auction last week -- with every single cent going towards the Michael J. Fox Foundation for Parkinson's Research.