raising a step son who has a brother from another father

by unknown
(south africa)

when i got involved with my husband who was then my boyfriend, i knew he had a son but i knew he was part of the package. few years down the line, his mother was blessed with another child from another man, little did i know at some point i will have to deal with him as well. The elder brother does not know that the little brother is not my husband's child.

my husband and i decided to take our relationship into the next level, got engaged and moved in together. His son would visit us occasionally on weekends or during school holidays, one day when my husband went to fetch his son for a visit "surprise, surprise" he came with the two boys. i was not impressed and tried to find out what was happening and he told me he had no choice but to bring them both because the mother left them alone and he couldn't leave the other one alone. i understood but told him that i hope this is not going to be a habit.

this continued and it was a different story all the time. in 2009 we got married and later on had our very own child, thinking the situation would change. The other brother does not come as often as he used to but when he comes no arrangements are done with me, he just comes. my stepson always tell his father that he wants to spend time with his brother and he does not see any problem with this, he says its innocent visits and he just does not get it when i tell him i do not feel comfortable with the arrangement as i end up having to take care of him as well when i was not even consulted before.

I'm really sick and tired now having to complain about the same issue over and over again. he just does not get the point

please advise