I chose a woman from different faction to marry, because I wanted a challenge, but this situation is so complicated it's not funny anymore.
Sayyid-invisus Lakhem allowed me to marry his sister Maulana Safiya and I got a quest. However castle where Lakhem was going to host a feast has been captured by Khergits. Since then nobody knows where Safiya is and Lakhem is waiting forever to host a feast.
As far as I know this bug may totally break any possible marriages, so I can't just abandon this quest and court someone else. I have some saves, but months before that, so I'd rather fix this situation. Is there any way, like joining Sarraninds, capturing Asugan Castle, hoping Safiya will reappear and Lakhem will host a feast?
Diplomacy could really use some fixes in this matter. It should be possible to cancel marriage proposal and then go for it again. It's not very realistic, but would solve this bug. Maybe this quest should be auto-cancelled when chosen town/castle is captured.