My Dad Left Us Because He Thought I Was My Mom's Affair Child But He Was Wrong - Reddit Stories
OP's dad found out that his wife had multiple affairs around the time OP and his brothers were conceived, so he got DNA tests and OP's test stated that he wasn't his dad's son. Now, it's been proven with a second DNA test that the lab made a mistake with the first one and OP is his dad's son. The dad wants to be back in his life and OP told them to kick sand.