James Franco: My little brother Dave is dating Zac Efron

Ahh, brotherly love — one of the sweeter parts of sibling-hood.

Not so nice? When your brother punks you, as James Franco did to little bro Dave Franco Thursday.

The actor posted on Instagram this hilariously Photoshopped version of an article featuring Dave and his Neighbors co-star Zac Efron.

"Effron (sic) and My brother, dating!!!!!! Congrats, boys! I'm so happy for you!!!" he captioned the doctored photo.

What a cute couple! (Although do you think Michelle Rodriguez is jealous?)