1) if Zach told you he was grounded, did he tell you what for? and if not then i think you should highly think about if you trust him or not cuz it sounds like he's making excuses to break up with you
2) if someone else told you he was grounded then i'm pretty sure he had that someone tell you that so that you'd leave him alone
i've had many boyfriends who've used the "grounded" excuse and when i'd call their parents would let me talk to them. i don't know about any of you, but if i was grounded from speaking to a specific person, my mother would never let me talk to them if they called. she'd tell them that i can't come to the phone and that as soon as i'm allowed to use the phone i'd call them back.
as for the best friend not liking you, mostly i would say furk them, but i've learned that if you can get along with yer man's friends then whatever he tells you is most likely truth
finally, as for him telling you about the spell ... the only reason someone really tells anyone that is to piss them off to push them away - and personally i think it's childish about that whole ordeal, and be reassured that a true wiccan (believe me cuz i used to study wicca and a good majority of my closest friends are wiccan)
cannot cast a hurtful spell on anyone simply becuz it's not in their nature ... the first and most important rule in wicca is "do what ye will and it harm none" - basically do whatever the hell you want as long as it doesn't harm you or anyone one else because it WILL come back to you 3-fold (which is the second rule)
all in all, i think you should just start looking for something better since he's obviously not man enough to tell you the truth to your face - i know i don't know his side of the story, in which case i could probably give you alot better advise, but that's the best i can do with what i'm given
hope it helps!!
"The best way to convince a fool that he is wrong is to let him have his own way."
- Josh Billings
+MWAH+ Shayne;P