...Sign it "Partha"; that'll
really creep him out.
Being serious, now:
1) That's not a lot of evidence to work off of.
2 & 3) I think you should just give him the box yourself. Best case scenario, he immediately gives you a huge moviekiss and you two begin feeding each other the chocolates. Worst case scenario, he ends the friendship, which means he doesn't deserve you. Anything in between works out in your favor, so go for it.
And remember, "I'm-a Luigi, number one!"