I must say, Lisanna is prime 'waifu' material and if her big sister is anything to go by, you'll have many happy years with a beautiful woman.
It's hard to dislike any woman in Fairy Tail really.
It's too bad that Mashima won't delve into the other aspects of the relationships that he's got going on becuase I'm sure that we'd get a ton of drama from Lisanna/Natsu/Lucy alone. Lisanna hasn't stopped liking Natsu from her time in Edolas and unfortunately, Natsu hasn't really had time to think about Lisanna and Lucy in that way unless Erza knocked him unconscious for some reason or other.