Grandma Jack - S8-E7
Other mistake: Larry entered Jack as "Grandma Tripper" to win the contest since the contest was only open to women. However, since Larry admits he didn't know there would be a bake-off and thought a winning check would just be mailed, then there's no reason to of entered Jack as "Grandma." He easily could have just entered Janet or Terri using Jack's recipe.
Answer: He's not a Catholic priest. He's a pastor, with the title Reverend, at a community church who chooses to wear a clerical collar. Some people still address pastors as "Father" though. I'm not sure of his religious denomination, but most pastors can marry.
Bishop73