"Another wonderful new mechanic, when you reach S rank with someone the lines they utter while you are rubbing their bodies become way more lewd.
Examples:
Leon: Do you want me? I understand. I too, want you, it's unbearable.
Lazwald: I also want to touch you, will you come closer?
Zero: It's lonely...it's agonizing. When you are not here (existing), it's just not right/good.
Camilla: When you do it this much, it's embarassing...
Camilla: The way you're using your hand feels sooo good. Very skillful.
Elise: Ahhh...You're sooo warm.
Marx (multiple examples): It's just the two of us, huh... Only look at me. Don't look away... Your eyes... They're beautiful. Don't make that face... I love you... Is there something you want to do here? Not anymore... are you my little sister. I want to touch you... This armor is a hindrance, isn't it? That face, only show it to me...? I want all of you..."
LEON'S LINES! (totally a sub!)
Ah... not there I said!
I l-love you...
D-don't stare at me like that!
Uu... Don't go tempting me like that...
! No, not there...!
I'm not used to this kind of thing....
It's so different when it's just the two of us...
Hm...?
What's the matter?
That feels good...
What are you planning to do to your little brother? ... just kidding
Your hands are so warm... i love it...
Look, just come closer
Hmm...? What do you want to do to me?
If you want me to touch you, just say so...
Do you want me? ... I know you do, I want you so much it's driving me crazy too...
CAMILLA'S LINES!
Hey!
No good?
My, already...
Such a cute kid...
You scamp.
Are you proud of my hair?
I thank you for your praise.
Such a good child.. I'll give you a reward afterwards.
My tiara's out of place.
Ara
Well
Aren't you the spoiled one?
What's the matter...?
Fufufu...
Well, if it's you...
Touch me as much as you like?
If it's you, do whatever you please.
Next time, your big sister will be doing the petting.
Ufufufu
Ahn...
Ara ara
Don't be so rough.
Yes.. You're skilled.
Are you interested in that?
Must you touch me so gently?
Can you really be satisfied by that?
Ufufu... Are you limp, I wonder?
Ufu
You...
Do that more...
Treat me well, right?
I love you... You, who are mine alone...
Good, come...
Do whatever you like...
You're very good at using your hands... Very skilled.
Y-.. yeah...
Ahhhn!
Ah, no more...
Doing this, is so embarrassing...
Please, be gentle with me.
No, if it's you...
Ah,... if you do that, then I...
I can't stand up anymore...
I'll only allow you to do this...
JOKER'S LINES!
I, I would also like to touch y... no, I said nothing
You're always so gentle
Ah... not there...
I love you...
I'm truly happy...
I'm such a sinful man...
I still can't believe, that you are mine....
You're so cute...
Do you love me?
I have... always wanted you....
We can't... it'll have to wait for tonight
No good... I don't think I can hold back any longer
https://www.reddit.com/r/fireemblem/comments/3avvj7/when_you_reach_s_rank_with_someone_their_lines/