He went through my facebook and broke up with me! Is that even right?!?

[YamiAmi]

This guy and I been talking for 3 weeks. I really really like him and he says he's falling for me. But one day this week he let me use his phone to check my facebook and I forgot to log out. And he saw a particular IM with a friend of mine I actually met on yahoo messenger. I said "I lubby <3" and it's an inside joke. I already told this friend how I feel about the guy I like, but hen the guy saw "lubby" he thought it means I want to BE with that guy...and he got mad and broke up with me. We technically weren't together yet because we were taking things slowly, but he got mad. Do you think he'll come back? Should he be THAT mad at what I did? I told him I have guys and girls as friends. I tell them all about him...I personally don't see what the big deal is...because all my friends know I really like the guy.