I have parental abandonment issues. It's hard to explain, but my mother sort of quit taking interest in my life when I was 13/14, and my dad and I were never really close until he broke up with my mother when I was 15, at which point we were really close until I was about 18, then he started losing interest in me again. It would be long and difficult to explain what exactly happened, and why I feel abandoned by my parents in a lot of ways, but I just do.
I often wonder what would happen if my dad decided to divorce my stepmom, or if my mother decided to dump her fiancee, but truth be told, I don't really see either of them becoming more involved in my life. With my dad it might be easier to reconnect, since he would have better judgement than to go looking for another date, and it would give me a chance to try reconnecting with him, but with my mother, odds are if she broke up with her fiance, she'd immediately find another date, as it's not really in her nature to "go alone". As such, it would still remain hard for me to reconnect with her.