They had a very toxic abusive relationship. Mary moved on and got married (later divorced). K Ci let substance abuse get the best of him but he seem to be doing ok. He performed at the soul train awards (I think) and was singing to Mary. Basically saying she the one who got away lol
Musically, they were good together, but their relationship was so toxic as hell. I remember K-Ci saying he was single in an interview when they were engaged, and the host played it which was so messy. I wish they would've made more music together.