Well, in the case of Lindsay Lohan, that's just your usual celesbian attention-getting. But, like nearsightedness or asthma, it's not impossible for homosexuality to develop later in life. Heck, I heard some guy turned gay after a car accident (rear-end collision?
That's not my joke.), though he may have just been looking for a quick buck in court.
Here's the thing: Right now, CNN is doing a segment on how gay characters in TV shows/movies is kind of becoming a "thing", and that's where I draw the line, because that's just bigotry in the opposite direction. Now, that's not a homophobic statement. I'd be just as irked if it suddenly became "in" to add tons of female, black, or handicapped characters to media just 'cause.