Sad boy, alert!

We never really got the reason for the breakup between cuties Justin Long and Drew Barrymore, but it's pretty obvious now that it wasn't something Justin wanted.

According to E! News the Mac Guy remains "distraught" over his split from the actress -- so much so that he has pulled out of the new movie "Whip It!" which Drew was directing.

"He couldn't stand working with her and not being with her," Justin's pal revealed. "He's too upset. She dumped him. She was hot and cold. One minute she was in love with him and the next she wanted to break up with him."

Poor Justin -- losing his girl, then a job -- dude needs a good boy's weekend in Vegas to heal a bit.