Why would Doris day

It's a movie. Better yet it's a pre-1970s romantic comedy, and has all of the unbelievably stuff of an ideal world.

Although also note that there were a good number of people who were really like that.

She DID know he asked her for sexual reasons...that was the whole point of the movie. She wasn't "that kind of girl", but agreed to go anyway to defend the honor of Upper Sandusky". She then broke out in hives to resolve the moral conflict.

But to save her own self respect, she talked HIM into going a second time, and resolved that by getting flat out drunk and diving off the balcony!

Mr. Shain felt sorry for her and gave her a job until she practically destroyed his company. Gee, what else could he do but marry her!

A great comedy that I never tire of watching.

Happens today. I had a coworker who met, in her words, "a gazillionaire" at the airport while she was waiting at a gate for a flight. A week later, she quit her well paying job (she wrote software) and followed him to San Diego.

Needless to say, it didn't work out. She came back about a year later, only to follow someone else on another impulse. I have no idea where she is today.

She was wary that he wanted sex from her but it seems she was holding out more hope for love than anything.
I was more disappointed in the "jokes" the characters made about beating up women who refused sex.

In the scene were Cary Grant goes to the pool for the 2nd time, the guy in the white tux said his new bride said she didnt want sex so he belted her. Carey joked and said he did the same to Doris right across the face.
When doris went back home, she told her flatmate she felt worthless bcz Carey didnt bother punching her bcz she didnt give him sex.
Shocking.
So she knew exactly what was going on.