You mean Dalia, Delilah is Nova (boom, I remember now !
).
To answer though, it didn't feel rush to me since they made the bet like days before it happened, like it didn't come out of nowhere. It did feel a little pushy when Orion started mentionning during such an emotionnal moment, but then he just give up easily and Dalia is the one who says "let's do it". I mean MC help her numbers of times and make her feel good and confident in herself, that plus the bet makes it believable in my opinion.
I mean dude, find me a straight male that can say no to this :
View attachment 2148978
She's flirting like crazy, they're alone together in a giant roman bathroom and adrenaline's pumping due to the fights that just happened. Plus it's probably illegal to say no to an Empress. And if it's not, it should be when she looks like this.
That's probably the case, like Annie. Very often there's one or two girls like this in this kinda VNs. If there's already attraction/love in the past, it makes it easier for MC to get close to them to begin with since something is already there. I mean if she didn't find him attractive, she wouldn't even have accepted the bet to begin with I presume.