I think it's probably because of their goals. They might have thought,"I'll ask her out when this is all done."And maybe because they thought 愛 can be a distraction to their work.Or maybe the boys have so much pride they think they're just gonna end up being dumped.Well, it wouldn't hurt to try right? How about あなた guys? What do あなた think? Now I wish Arakawa-san is 読書 this. She doesn't know how many people would like to see Ed and Winry または Roy and Riza kiss.I wish there was a psychologist in the series,so that way Winry または Riza won't have a hard time thinking,"What do men want from women?" または Roy または Edward would think,"How am I supposed to impress her?"