Jessica's Romantic Ringtone!

Jessica and Tony (Rick Diamond/WireImage)

With schedules as busy as theirs, Jessica Simpson and her quarterback boyfriend Tony Romo can't be together all the time.

So we hear that Jess, 28, keeps beau Tony, also 28, close by having the Dallas Cowboys’ theme song on her phone!

Very cute -- but that doesn't stop her buddies giving her a hard time for being so slushy!

“Jess’s girlfriend was teasing her because it kept ringing with her boyfriend’s team’s tune,” a witness at Chicago’s Rockit Bar & Grill tells OK!.

“It was funny.”