Fan Xian married Sisi in the eighth chapter of the novel Joy of Life.

Fan Xian married Si Lili in the eighth chapter of the novel Joy of Life. The specific time was not mentioned.
According to the information provided, Fan Xian and Sisi indeed had a relationship. Sisi was originally a servant girl sent by the Fan family's grandmother to Fan Xian's side. Later, she became Fan Xian's concubine. They had a daughter named Fan Shuning. However, there was no further description of Fan Xian and Sisi's relationship, so the information provided did not give a clear answer as to whether they were together or not. While everyone is waiting for the TV series, you can also click on the link below to read Joy of Life's novel to understand the plot in advance!
Fan Xian and Silili were not together. Silili was Fan Xian's servant girl. She later became Fan Xian's concubine and gave birth to a daughter. However, there was no mention of Fan Xian and Silili developing further or combining together. Thus, Fan Xian and Silili were not together.
In the search results provided, there was no clear mention of what Si Lili had said to Fan Xian in the dungeon. Thus, based on the information provided, it was impossible to determine what Si Lili had said to Fan Xian in the dungeon.
Si Lili was the supporting actress in the TV series Joy of Life, played by Li Chun. She was a descendant of the Qing royal family. She had fled to Northern Qi and worked at the Drunken Immortal Residence. Si Lili was originally a spy in Northern Qi that Fan Xian had used. However, as the two of them interacted in the carriage, Si Lili developed feelings for Fan Xian. Fan Xian's feelings for Si Lili might only be those of an ordinary friend of the opposite sex. In addition, Northern Qi's little Emperor Zhan Doudou had a complicated relationship with Si Lili. Some things happened between them, and in the end, Zhan Doudou became pregnant and gave birth to a daughter, named Red Bean Rice.
Fan Xian married Lin Wan 'er, Liu Sisi, Haitang Duoduo, Si Lili, and Zhan Doudou.
Fan Xian married five women, including his wife, Lin Wan 'er, and his concubine, Liu Sisi. Other than that, he also married the Northern Qi Saintess Haitang Duoduo, the Northern Qi Imperial Consort Si Lili, and the Northern Qi Empress Zhan Doudou. The person Fan Xian loved the most was Lin Wan 'er.
Fan Xian married Lin Wan 'er, Liu Sisi, Haitang Duoduo, Si Lili, and Zhan Doudou.
Fan Xian did not marry Fan Ruoruo. Although Fan Ruoruo had confessed to Fan Xian, Fan Xian only treated her as his own sister. In the end, Fan Ruoruo married Li Hongcheng, the son of King Jing. Therefore, Fan Xian did not marry Fan Ruoruo.
Fan Xian did not marry Fan Ruoruo. Although Fan Ruoruo had confessed to Fan Xian, Fan Xian only treated her as his own sister. In the end, Fan Ruoruo married Li Hongcheng, the son of King Jing. Therefore, Fan Xian did not marry Fan Ruoruo.