Dwight was married to Sherry when they joined the Saviors. At one point, Sherry joined Negan's harem, earning herself and Dwight an easier lifestyle within the Saviors. Negan doesn't allow infidelity, he had to punish Dwight with a hot iron to the side of Dwight's face after Dwight had been caught seeing Sherry.
After Dwight, along with other members of the Saviors, killed Abraham and took Eugene hostage, he showed up in front of Alexandria's gates and demanded from Rick to let them in or he would kill Eugene. Eventually Eugene managed to break free and get back inside Alexandria thanks to the distraction provided by the heavy fire power while Dwight and the others decided to retreat.
Dwight later serves as an inside man for Rick, killing several unnamed Saviors and revealing where Savior outposts are located. After Negan is taken prisoner by Rick, Dwight begins to lead the Saviors and continues to work with Rick and the other communities.