Is Giving Up Primary Custody the Same as Abandonment

My question involves a child custody case from the State of: Nebraska

My boyfriend has a 3 year old son that he and the mother share joint custody of. My boyfriend is the sole provider and care taker, covering all expenses, the mother will only see him once or twice a week and does not provide financially because she does not work and relies on government assistance. My bf has lost one custody battle already. Although the mother is married she does not allow my boyfriend to speak or date other girls (she does not know about me), if she finds out that he is she will take his son away.

The mother recently moved to California to be with her husband leaving two of her kids behind, my bf's son and another child from another relationship. She intends to stay there permanently and will only see her son two months out of the year (summer). Could this be considered abandonment? Or not because she intends to visit.

Ir's best that you keep out of your boyfriend's business.

(But for the record, of course this doesn't constitute abandonment)