(showbizspy.com) - Lindsay Lohan and Samantha Ronson are set to prove they are more than "just good friends" -- by getting married in a secret ceremony in LA later this year.
The pair -- who are yet to officially confirm they are in a relationship -- will exchange vows to stay together for life, according to Britain's News of The World newspaper.
The Mean Girls star's mother, Dina, is said to have told pals she wants to "welcome Sam into the family" with a lavish do, including drinks and canapes for Lindsay's friends and relatives.
Lindsay, 22, has even bought her clothes for the occasion -- a white mini-dress by Chanel. Sam, meanwhile, has joked that she'll wear a black groom-style suit complete with a top hat.
A source reveals, "Dina is still working on the date of the party but it's looking like towards the end of the year.
"Lindsay's new album Spirit In The Dark is out in November, so I wouldn't be surprised if it's around then.
"They've been keeping the relationship quiet for months and trying to pass each other off as 'just good friends'.
"But they've decided it isn't a fling, it's for life- so they want to make their romance public."