I don't know if this is exactly a love card - but it did make me laugh out loud - and I am sure that whomever you give it to will as well.
sapling press has teamed up with josh hara (@yoyoha) to bring you his hilarious twitter feed in stationery form.
inside: blank
size: 4.25 x 5.5
paper color: yellow
envelope: 100% post consumer brown bag kraft
ink: black, red + blue