Your aunt's daughter is your first cousin, and her son is your first cousin, once removed.
your cousin
They would be 3rd cousins.Grandma-GrandpaMom-Auntyou-cousinson-3nd cousinthe diagram is supposed to show that if your cousin has a baby it would be your son's 3rd cousin because your cousin would be his 2nd cousin.
aunts, cousins, daughters, sons, and friend.
Sons would be plural and son's is possessive. Tickyul
A nephew is a cousin to his aunt's son.
great nephew
Your son and your aunt's son are first cousins once removed to each other.
You do you call your sons's son your "grandson" !
Assuming that "his aunts" have reached the age of majority and that "your son" has a passport with the VISAs required by Morocco for citizens of "your son's" country, there should be no issue.
Use "son's" when referring to something that belongs to one son. Use "sons'" when referring to something that belongs to multiple sons. For example, "My son's toy is on the floor" (one son), or "The sons' room needs to be cleaned" (multiple sons).
to make it easier lets say ' aunts son' so that is your cousin
Your mother's aunt's son is her first cousin and your first cousin, once removed.