Ugh partner work. I'm sorry OP. Maybe talk to them about it, or run it past the person who told you to do the assignment?

Just say they copied you, that is nothing but plagiarism. But say it first before he tries to flip it on you.

Hurry and show your boss YOUR thing

go report the plagiarism, it's not fair that he'll probably get the good results when he didn't put in any effort at all and maybe cause you a lot of trouble. it's just not right and you don't have to feel bad about reporting him at all, you're just helping other people. if he can do it once, he can do it again.

Hey at least you turned it in first, but still report it before an my suspicion is placed on you!

Isn't the point of an open invite to allow anyone to go?

Report him. If you say something before you hand it in, they most likely won't punish you.

kill him, it's your only option

Hopefully there's a record of when you submitted your work. That way there'll be proof that your coworker copied yours.

Why would you be checking your peers work to make sure you didn't forget anything /after/ you'd already uploaded it? It's a little too late then, OP. You're an idiot, but not an idiot who deserves to be plagiarized.