"Tammy would like to see Ryan with a women who's not in the movie business because she feel that, ultimately, actresses put their careers first," says the source. "And she thinks Blake is pressuring Ryan into settling down before he's ready. He [also] rushed into his first marriage, with Scarlett Johansson ... [Tammy] says when they have kids, Blake and Ryan should raise them in Canada because it's safer. Blake refuses to even consider that, saying that she has to be in New York for work."

The mama drama came to a head during a May 6th dinner at the Reynolds family home.

"When Tammy started grilling her, Blake left the room and had a meltdown," says the source. "She told Ryan she wanted to stay at a hotel for the rest of the trip ... Tammy says it proves she's right: Blake's a diva. Ryan is torn between them - and in an impossible position."