Answer:
If he is your uncle by marriage (married to your aunt) which later ends in divorce, he is no longer truly an uncle in the technical sense. However, he may still be said to be your uncle in the sense that he is the biological father of your cousins. Obviously, if he is blood-related to you and he gets a divorce then he is still your uncle.
although you may not have cousins that he is the biological father too, but i sposed you could stilll say he was your uncle?