Lyriel and her Hornyness: Have to admit it, on some occasions it was annoying, especially when secret hunting. If she weren't reacting as bitchy as she does (intimacy penalty) I'd have prosponed her boning.
BUT: You could turn it into a mechanic, the hornier she gets the more willing she gets to do something lewd.
Just some examples:
[spoiler]
When tanning at the pool, she could start sucking you off and if in overdrive she might drop her panties and present herself with cheeks pulled apart, begging you to ram her hard. Maybe have one of the other girls drop in accidentally right when she's in the throes of orgasm.
When Rae is cooking breakfast, properly dressed in an apron, she might want to watch instead of leaving in a fake huff, or even join you. Lyriel breaking her fast on a Raeflavoured Creampie, now that I'd like to see :)
In course of the Manga Research Club, there are also possibilities to have Cait join, or rather vice versa, as in Lyriel "accidentally" walking in on you and Cait while you eat her out.
Judging by the Thumbnail, Lyriels backdoor is going to be open for pleasure sooner or later, she could experiment by herself when showering, could lead to some anal with her spread on your arms, back to you, viewing herself in a mirror, pussy wide open and dripping while her ass gets fucked. On the other Hand, might want to give that one to our favorite demon lass, Succubus Magic making her lighter and such, as even a 100lbs girl tends to get heavy after a while ^.^
Also, I was wondering all the while why Lyriel is the only girl who actively seeks you out, asking for sex. I would have expected Rae, being the obvious "target" for that.
But all in all, keep it, add something similar for Rae I'd say and I mean a bit more aggressive than laying on your bed.
And while we're there, I'd like to request an oral option here. Walking in, saying nothing, grab her slip and pull it to the side or rather off (seriously, have you ever done that? Chafes, you have pull it back every 2 seconds and in general it sucks, this only works in porn apparently) and kiss her on the pussy, commenting "Missed you, beautiful" - to the pussy, ignoring whatever Rae says. Ultimately leading to a proper shag and creampie.
And lest I forget: Sleeping with Rae or Lyriel should have the option to wake up together, making creative use of some morning wood and maybe, if the girl has nothing better to do so to speak, spend the entire day 'tween the sheets shagging.
[/spoiler]