My friend Luke called me a "it", i know he is jokng. But it kind of hurt. Am I being over sensitive? Or?

Big hug! No one is an "it" and you need to let your friend know that's not acceptable. If it's a case of not knowing, use it as a learning experience. Hugs, Devlyn

No, you're not being oversensitive. I stick up for guys most of the time for name calling and trashing and so on but that is too far. You're not an "it" and definately let him know.

No that doesn't sound funny at all. I can't imagine the context where that would be alright or not mean. I don't focus on words so much as I focus on tone. Tone is what matters and intention. But "it is dehumanizing in a way that othe words simply aren't. If someone calls you a ->-bleeped-<- and not in a fun joking manner at least you are still a person. It is dehumanizing.

Gross disrespect, but some people don't have a filter between brain and mouth, so it's possible he didn't think about how it would come out.

This is very definitely a sore spot for transgender folk. Please, for your own peace of mind, explain to him why "it" is a no-no.

I don't think you are being overly sensitive about this at all.  That's a very rude thing to say.  It's possible he didn't mean to offend you, but you should tell him why it is so hurtful. 

A joke is a joke, but I fail to see how calling anybody an 'it' can be seen as a joke.

Seriously. This is not funny.