Who Is Cersei's Baby Daddy on Game of Thrones? An Investigation

Why not: Euron travels from King's Landing to Lannisport with his fleet so quickly, we doubt he had any time to do the deed with Cersei. Plus, she seems intent on keeping him at bay (literally) as long as possible, "until the war is won." Not to mention, Jaime doesn't trust him and would never allow Euron and Cersei to be alone long enough to make a baby.