Theroux, 42, apparently wants his fiancee to cut down on her alcohol consumption but the former 'Friends' actress is not keen on the idea, reported Daily Mirror.
"Jen is totally capable of quitting and has never gotten into trouble with her love of vino but Justin doesn't like how she'll easily down a bottle of wine a night without batting an eyelid
"He really wants her to quit and has been pushing for a non-alcoholic wedding - an idea that was met with great laughter by Jen and her girl crew," a source said.