AceShowbiz -

Sienna Miller is said to have finally agreed to marry boyfriend Rhys Ifans after the actor proposed for a third time. The pair are now excitedly planning a summer wedding, according to U.K. reports.

Rhys first proposed to Sienna last November when he sent the actress a cryptic message in Welsh, which read "Marry This Misfit". "She didn't give him an answer straight away, she's since been thinking about it more and more," a source in the know revealed at that time, adding that "Sienna is being very coy since the proposal. She's been avoiding discussing the issue with friends and some of them are starting to think she may have said 'yes'."

Didn't get a 'yes' from Sienna, Rhys tried his luck again at her 26th birthday party in December, hiding a ring amongst a pile of presents. On the actor's third proposal which got a 'yes' from Sienna, a source told the Sunday Mirror, "Rhys has admitted he and Sienna are getting married. Everything is supposed to be hush-hush, but Rhys is over the moon and finding it hard to keep quiet ... he can't believe she finally said yes."

The source added, "Although Si and Rhys have a lot of famous friends, they will keep it low-key. They won't be signing up to some magazine deal."

The guest list, still according to Sunday Mirror, will among others comprise of everyone from Kate Moss, Sadie Frost, Davinia Taylor, to Sienna's best friend Keira Knightley and her boyfriend Rupert Friend.

Concerning their summer wedding plan, Sienna and Rhys are now reportedly looking for a home in Oxford and a cottage in Wales.