If true, that's more troubling than if it belonged to another girlfriend; brings new meaning to the term 'Mama's boy'

Maybe his mother is bringing him provisions that he can't afford for some reason, potentially because of house payments.

What if... he lives in his mother's house?

Or maybe he has another girlfriend and she likes it when he calls her "Mommy"

Good ol oedipus rex

LMFAO!!

if he doesn't live with his mom I cannot see how that leaves him any better off, if anything that's just creepier...

What if his mom lives far away and had come into town to visit him? It's not that unreasonable that she might spend the night, and it's easy to accidentally leave something like that behind if you're careless. It's a bit awkward for everyone, But I don't think it would make him creepy.

She could also live close by and do his laundry and hers got mixed in. Would make it significantly less creepy, but doesn't make him any better boyfriend material.

Wow that's disturbing if you think about it.

Judging from your title it looks like you've already made the right choice here. Good for you.

OMG, it could be from an ex girlfriend for crying out loud!

Laundry mix-up? Mommies gotta feel sexy, . too!

Fifth

In the game of wincest, everyone loses. Period.

The location explains it all...

Ha! Was gonna post the same comment. You beat me to it. ;)

Maybe it's his. lol

If miraculously, he wasn't lying, I would be very disturbed any time I heard, "I love you mom!" for quite a while. Hell, just thinking about this makes me not want to hear anyone use that line for a while.

Ungrateful child, call your mom and tell her you love her

If there was panicking involved he was most likely lying. Leaving you two options, it's another girls thong... or it's secretly his and he has a secret life you don't know about.