SPOILLER!!!!!!!!!!!!!!!!!!!!!!!!! Why did Henry get so mad when Abby kissed Jimmy when they were saying goodbye?

Because he loved her. He was infatuated with her. The way they kissed so deeply (though she had a reason to french him like that *winks*)... that drove Henry nuts. And in his twisted mind that shouldnt be happening... she should l’amour only him, only Henry.

Because the l’amour of his life was french s’embrasser some other guy right in front of him... Which is why he hit her when she a dit she loved Jimmy.
In Henry's defence, he really did l’amour her. toi can see it in the scene where he throws the boarding couteau away. Of course, most guys choose to tell toi they like toi par buying toi chocolate, not par killing all your Friends and family but... To each his own and what not...

i dont know how its a spoiler...anyway...yeah i think henry likes abby....

i agree, how is this a spoiler? but henry got mad at abby because he didnt want abby to l’amour another person cuz henry should be the only one she should love. plus he is her brother so he tried to protect her even though he was waay too over-protective.but it was a good plan that abby kissed jimmy so that she could give him a nail so he could get himself unlocked and it worked. the series is already over and we all know how it ended. and it was a BIG shocker to me. happy that henry died!

ok here goes henry has this obsession with abby he wants it to be him and her only kinda freaky the l’amour is incestuous l’amour when she kissed jummy (and gave him the cuff key i might add) henry flipped cause he loves her so much she wanted to create a distraction to give jimmy a chance to get free

He gets mad because he loves her and the other times they kissed he wasn't around to see it, and if he tried to stop it before he would have blown his cover.

he loves her

Well, when The Girl of Your Dreams is french s’embrasser another guy right in front of you, that can definitely make toi lose it. Besides, Henry gave her the chance to say goodbye and was mad that she took it ;) He was pissed that he allowed the situation to turn like that, so he tried to get the control back and there's this 'I l’amour him!' from Abby (honestly, can toi blame the girl? ;D).
par the way, did toi noticed that's kinda sick? After all Henry is Abby's half-brother and he knows it and toi can't say it's brotherly l’amour he's got for her.