Nicolo has little to no experience with sex or romance. But he knows Yusuf has had several flings and partners and seems to only take an interest in experienced people. This Nicolo is sure means Yusuf would not want him. So to gain experience (at least some sexual experience) and hopefully make it so Yusuf might one day consider at least bedding Nicolo if nothing else, Nicolo tries to learn what he can about sex and romance. This he does both by flirting and having sex with some people that flirt with him during their travels and by talking about it (to learn some tips) with the sex workers that he met and helped with something a few times.

Yusuf is miserable because he was thinking Nicolo wanted nothing to do with sex or romance at all. But maybe Nicolo just wanted nothing to do with anything romantic with Yusuf? Why else would he be sneaking off with the baker of the village they are staying in? He turned Yusuf down when he tried flirting with Nicolo in the past.

(Nicolo did not turn Yusuf down, Yusuf was just being way too subtle, like a flirting ninja!).