Eva Longoria & 'Ready for Love' Star Ernesto Arguello -- JUST FRIENDS, BUT ...

11:30 AM PT -- Sources connected with Eva tell us, it's no big deal ... several cast members of her TV show have been crashing at her house because they don't have somewhere to stay in L.A..

Eva Longoria insists she's not dating "Ready for Love" bachelor Ernesto Arguello -- but the two are definitely LIVING TOGETHER ... TMZ has learned.

Sources familiar with the situation tell us ... Ernesto -- a 33-year-old successful civil and architectural engineer -- has been crashing at Eva's L.A. pad recently.

We also know ... Eva and Ernesto have been hitting the town together too -- hitting up Chateau Marmont on the Sunset Strip on Sunday night ... and the exclusive Soho House on Monday.

Despite the connection, Eva is adamant they're just friends -- and just yesterday she tweeted, "Sorry @ernestoarguello is NOT dating me."

But wait, there's MORE -- we also know Ernesto ain't the only dude from her dating show crashing at her house ... Tim Lopez (the singer from Plain White T's) has also moved in.