If you kick her out once does that end the romance?

I've been paranoid about this in all my previous games so I haven't ever kicked out the romantic interest.

I think it does ... but i'm not to sure ... its best that you check out Extremist's romance guide. Hopefully that'll be more helpful.

If you kick her out for more than three(3) days then the romance gets broken. Or if you kick her out in an argument or in the middle of a romance quest it gets broken (It is different with Jaheira though)

If you kick her out once, it's over. Jaheira is the only NPC whose romance is not broken if kicked out. Note that this does not apply if they leave on their own, or

SPOILER
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Get taken by Bhodi

No. Jaheira is set to instantly break the romance if you kick her out of the party. All other "lovers" will wait for three days just as 8people said. And yes, there is a bug within Jaheira's dialogs that won't stop her romance at certain point if you kick her out, but don't pull this trick out (patches, fixes - hint).

When I say kick out, that means you specifically order the NPC to leave or you give such badmouthing present that even a dog wouldn't lick or you simply don't want to listen the romance dialogs so you silence the NPC before the nice music in the background is over.

I think if you kick them out during chapter four or five ends the Romance as well, that may just be rumour I am not sure