#LHHNY couple Mendeecees Harris and Yandy Smith might be honeymooning in a federal prison ... because the groom just plead guilty to running a drug ring in upstate NY.
Harris struck a plea deal in the case, and will now face 5 to 40 years in the federal pen, and/or a fine of $5 million. The feds nailed him for a drug trafficking operation that shipped cocaine and heroin to Rochester for 7 years.
Harris will remain free on bail until his sentencing in August -- good thing for him ... since he and Yandy are getting married next month on "Love & Hip Hop Live: The Wedding." By the way, he also has to surrender all his paychecks from 'LHH.'
The only good news for Yandy when her hubby gets locked up ... she'll get back most of the $200k she put up for his bail when he originally got busted last year.