Cat Hates Boyfriend suddenly.

Question
Let me start off by saying, I have the most adorable, lovable cat in the world. She sleeps with me every night (and by with me, I mean ON me.) She sits next to me while I'm on the computer. She's super playful. With ME.

She's about 5 years old. She's lived with me alone for the last 4ish years. She's always a little weird around people. They aren't allowed to touch her until she feels comfortable with it. She tends to be better around girls than guys, but we still do the hand sniffing thing so she figures out who they are. She hasn't been around TONS of people, but a few of my friends here and there.

She was weird around my boyfriend when we first met, but just for the first month or so. Then she would sit by him, sleep on him, let him pick her up. She'd actually sleep on his side of the bed with him, instead of with me. He saw her every day for about a year and a half.

Then my boyfriend got an extended internship 10 hours away, and was unable to come home for 3 months. When he finally did get to come home and stay, he walked in the door while I was holding the kitty, so I gave her to him. AND SHE FREAKED OUT. BIG TIME.

Hissing, SCREAMING (blood curdling), wouldn't let him walk within 10 feet of her without screaming bloody murder (at a yelling human volume), and this weird sound which almost sounded like a talking human. Puffed up fur, puffed tail. She looked both terrified and pissed. Then she just sat in the corner and growled at him. He stayed with me for 5 days, and she got A LITTLE better, but not much. She was fine if he was out of the apartment and just I was home, but the second he walked in, she'd start screaming and hissing again. She basically just hid under the bed and growled for 5 days straight. But when he left, she was totally fine.

And she is still fine. 3 months later. BUT... he's coming home next weekend for a few days. And I'm terrified she's going to do it again.

Do you know why she's doing this? Or what I can do to stop it? I don't know if she's:
A) mad he left (he spent A LOT of time with her)
B) jealous that she had me all to herself for 3 months and then she had to share me
C) or if she forgot who my boyfriend was and she thinks he's a stranger now.
Or something completely different!

Help would be greatly appreciated!

Answer
Believe it or not, she is actually VERY angry that he left and is basically even more angry that he thinks he can just come back into her life. He will honestly have to start from scratch and pretty much "kiss butt" for her to forgive him.

I wouldn't recommend just having things go back to normal before he left, it's not going to come that easy to her. And she simple wouldn't allow it. I would do things, such as let her come to him. I would not have him "beg" his forgiveness. Because, it's going to be on her terms anyway. She is basically having a hissy fit and will need her own time to come out of her stubbornness, so the best you guys can do is let her sulk and moan and groan and she's ready, she'll be ready.