As we reported yesterday, 2 burglars broke into 50 Cent's Connecticut Mansion and were caught hiding in the closet drinking wine.

The guys who were arrested inside 50 Cent's Connecticut mega-mansion weren't trying to steal anything -- they just wanted to get hammered in the lap of luxury ... at least that's what they're telling people.

TMZ spoke with the sister of Alexander Hernandez -- the guy who was found drinking wine in Fiddy's closet when cops arrived yesterday -- who tells us Alexander is claiming he and the other suspect just wanted to "hang out" at 50's place because they're both huge fans.

She adds ... Hernandez is claiming he never tried to steal anything from inside the house -- they only wanted the "thrill" of getting inside.

As we previously reported, cops say both men were inside Fiddy's pad -- and in possession of weed -- when police responded to the home.

Alexader's sister also tells us family members are concerned about her brother -- because he's still in police custody and could possibly miss his newborn baby's first Christmas.