I personally think that Natsu and Lucy are in love. In the very first episode with Borra Lucy was under his spell but the instant she saw Natsu that spell broke but it didn't for the other girls. As for Natsu I believe it was season 3, they were fighting Hades guild (sorry I forgot the name) and there was thar dude who had a voodoo doll. Natsu told Lucy to run when the voodoo man was smashing her head into the ground but Lucy said she'd rather stay with him. I personally believe that's when Natsu realized he was in love with Lucy. Though I believe their are many other moments when he could have realized his love for her that one is just my favorite. As for Lissana and Natsu shippers Natsu and Lissana loved eachother as kids. Kids that young often don't even know what true love is. It was most likely puppy love and they believed it was more than puppy love. As for Natsu being upset about the lost of Lissana when he thought she died who wouldn't be upset? He lost a friend,a guildmate,and a comrade,also family since everyone in the guild is family. If I lost a family member I'd mourn over them forever personally.
