Ryan Seacrest Out Ridin' with His Ex-GF

Ryan Seacrest is doing some backpedaling with his ex-GF, Shayna Taylor.

They broke up about 2 years ago, but looked like they were very much back on Sunday during a bike ride on Venice Beach.

We're told they're not officially a thing again ... yet, but Shayna was his date to Guess co-founder Paul Marciano's wedding in Bora Bora over Thanksgiving weekend.

Maybe Seacrest's finally got himself a ride or die.