They're all like bi or pan or something. Cuz Sam and Dean have both banged quite a few girls, but Destiel is a thing and Sam could totally be gay. Also, Gays. Adorable and so is the entire cast of this show.
No Samson did NOT get his power from his hair! He got his power from the Nazarite vow that he took which includes not cutting your hair. The power was given by God not his hair because that would be stupid.