Responses
I agree, also I think it runs in his family too
Yes, but the way it was discussed in the chapter, JJ seemed to not be as bothered by it. I mean he somewhat understood why. He was a bit uncomfortable when he visited Leo's family in Italy but he seemed like he got it, it's the culture. But it was indeed unfair that Leo gets to be jealous when JJ just talked to others.
Could it be that Leo is touchy feely with everyone cause he's Italian? I mean, not to stereotype, but... Ehe. If so, then Author really did their research.