One of my sims, Sonya had a baby called Jordan and then broke up with Jordan’s dad Sam because he tried to kiss her twin sister. Jordan stayed with Sonya who remarried and had another child, but then through story progression (and the fact that he was horrid), he ended up being kicked out of home and went to live with Sam. Sam had just had a baby with his new wife Tori. Not long after Jordan moved in Tori and Sam broke up. Jordan is now dating Tori.
Jordan is dating the mother of his half-brother.