"Why would he give this to me?"
Because you are stupid enough to go there with someone that obviously wanna bang you and end up in a rape situation.
For real the plot now is gonna be "maybe he didnt wanna marry me because he didnt feel good fucking me so i gotta get better practicing with others"??? Dunno why but i see that one coming together with her being jealous because he might or might not be with someone else.
These girls are all crazy with tons of emotional baggage, except the eldest sister who’s too pure. No gf material. If this wasn’t a pornhwa, a smart MC would just walk away.