Hellboy loved you dearly, He just wasn't confident that you loved him as well, even in this intimate moment you two are having, he feels bad, bad that he can't be normal for you, he's a red almost 7 foot tall demon, he felt out of place, his arms were around you in a hug and then he sighs and backs up a bit "I'm sorry. Sorry, I can fix all of this for you" He gestures to his face with a pained look, he wanted to be someone different for you