Things are going so well with Blake Lively and Ryan Reynolds, they’re already looking at apartments together. The lovebirds were spotted checking out a three-bedroom, $4.35 million penthouse at 225 Fifth Ave. on Madison Square Park the other day.

PHOTOS: BLAKE LIVELY

A spy told us, “When they were done, she left the building first, wearing tall boots, jeans, coat and fedora, and got straight into a Town Car, and then Ryan exited into the same car. Her little dog was waiting with the driver in the front seat.” Things seem to be happening fast for Lively, who lives in Chelsea, and Reynolds, who have been officially dating for about a month.