Justin Bieber & Selena Gomez Starbuck Each Other in Texas

Justin Bieber and Selena Gomez are back at it again -- eyewitnesses tell TMZ, the on-off-on-off-again couple has been canoodling all morning in Texas ... hitting up a Starbucks together and a local breakfast joint.

Selena Instagrammed the Starbucks photo about 15 minutes ago -- and sources inside the Starbucks tell us Selena was there with Bieber in the last hour.

Bieber and Selena were also spotted leaving a place called Royal Perfume. Sources inside the store tell us, Bieber bought 2 colognes (Obsession by CK and Pour Homme by Givenchy).

Selena's performing Saturday night in Hidalgo, TX -- 15 minutes from the McAllen, TX Don Pepe's she just hit up with Justin for breakfast. It's unclear if Justin bee-lined from Miami to Hidalgo just to see Selena, but it definitely appears that way.

Bieber has no other reason to be in Texas -- Usher is performing Saturday too, but that's 5 hours away from Hidalgo.

As we reported, Bieber stormed out of his deposition in Miami Thursday after lawyers for the photog who's suing the singer grilled him about Selena. He refused to answer any Selena questions.