Yeah, like "Fall in love" is a singular event that doesn't mean she stays in it.
Commands like "You are in love with me from now on" are more effective there, as they establish a new state
I get the feeling that the girl in this comic would have stayed in love with him if he asked to get laid, but her love meter dropped back to 0 because she was disgusted that he was only asking for seeing her panties and not anything else like groping her.