I am currently reading, 'My name is Red' by the acclaimed Turkish author, Orhan Pamuk. In the book, as part of casual conversations or character thoughts there are several allusions to homosexual relations between an old person and young man (an apprentice?).

Sometimes these are attributed to the other sect (or other person) to indicate that the people people engaging in such relationship are bad and immoral. However, there are even instances where it seems that homosexual relations between an old patron or master and a young slave was accepted by the society of the times. Though such homosexual relations are not mentioned in the context of marriage. Marital relations seem to be exclusively heterogeneous. Also these relationships seem to be exploitative with respect to slaves and apprentices (rather than among two people of equal power).

I wanted to know, whether such homosexual relations as described above were part of normal social milieu in medieval Turkey/ Ottoman empire?

The time period when the events in the books takes place is 1591 during the rule of Ottoman Sultan Murat III.