This is why aluminum foil exists! FYL. You probably have to bin it now.

And yet something did go wrong.

This is what happens when you take shortcuts!

For the record, Stouffer's lasagna is baked in the - oven - a regular non-microwave oven - with the plastic on, per instructions and by design.
Not taking it off before serving... yeah, oops

Technically speaking - if nobody removed the plastic - everybody forgot. So you're free to blame whoever you choose #lifehack

In what world is serving your girlfriend's parents a pre-made oven dish not the definition of something going wrong? Those are for when you are super lazy/tired after work and can't be bothered to make anything, not for entertaining.

Maybe OP isn’t the best cook? Would it have been better to serve burnt/undercooked/overseasoned food?

If OP (an adult) can't make an edible dinner, OP shouldn't invite people over for dinner. There is nothing stopping OP from inviting his girlfriend's parents OUT to dinner, or over for Tea or something. But yes, something that was burnt or under seasoned would have been better than something with plastic wrap melted into it.

Also, every adult should be able to make at least a few edible dinners. I'm not talking gourmet food, but cooking pasta and warming up sauce is super easy and takes less time than some store-bought casserole and it tastes better. The only downside is that you have to pay a modicum of attention to it rather than putting it in the oven and forgetting about it.

Should have bought takeouts from a nice restaurant and put them on dinner plates.

mom sounds like a stuck up cunt. she can make her own dinner early if she had to ask "pointedly."