What is my relation to someone who's grandmother is my grandfathers sister? So my grandpa and his grandma are brother and sister

Sooo, it sounds like your mom or dad (whichever one is the child of the grandpa you're talking about), and his mom or dad (whichever one is the child of the grandma you're talking about) would be cousins, so I guess you two would be cousins of some sort as well (if I understand correctly... )