The pair sparked fevered gossip about the extent of their friendship when they were spotted kissing and cuddling in Cannes, France earlier this year.
And despite continually refusing to confirm their relationship, the Mean Girls star recently professed her love for Ronson in a candid interview with Harper's Bazaar magazine, declaring: "She's a wonderful person and I love her very much."
And the pair have barely left each other's sides since - but sources suggest the intensity of the relationship is dying out.
It is claimed Lohan is getting tired of Ronson's constant presence - and is starting to question her own sexuality.
A source tells British newspaper the News of the World, "Linds is on the brink because Sam won't leave her side. Whenever she does, Lindsay's on the phone telling her mates she's decided she's not a lesbian.
"Of course she still has feelings for Sam - but she also feels like she has to escape."