Mila Kunis and Ashton Kutcher are planning to get married in a registry office. The couple, who got engaged earlier this month, are expecting their first child together and want to tie the knot in April before their new bundle of joy arrives. A source told The Sun: ''They are planning to get married in L.A. in April. They just want it to be made legal so are happy with a registry office. Mila, especially, wants it to be very low-key, with just their family there and a BBQ in their garden afterwards. She doesn't want to do anything showy or over the top.'' Though they are planning low-key nuptials, Ashton wants to mark their marriage with a big celebration later in the year. The source added: ''Ashton wants a party for all their friends later in the year in the south of France, which Mila is up for, depending on how they cope with having a baby.''