Jennifer Aniston was in character on the Wilmington, NC, set of We're the Millers yesterday. Jen returned to work after an exciting weekend — Jennifer Aniston's engaged! Jen accepted her now fiancé Justin Theroux's proposal on Friday, his 41st birthday. His rep confirmed the happy news with a statement that read, "Justin Theroux had an amazing birthday on Friday, receiving an extraordinary gift when his girlfriend, Jennifer Aniston, accepted his proposal of marriage." We're celebrating their big news with a look at Jen and Justin's sweetest moments.