The end line is about the difference between "I'm being selfish because I fell in love and it can't be helped!" And "I'm making personal sacrifices because I fell in love and it can't be helped."
Also I'm sure "offering a body" is just going to be marital duties at this point.
I generally hate the genre where the ML is mean to the FL and she falls for him anyway, but this one is okay because he might tease her but he's the one who still loses.