This movie shows the smug attitude of the college age
It reminds me of what a comedian said about how it was amazing how smart his parents became over just a few years. What he meant was that he was stupid and didn't know anything about life so he didn't understand the parent takes on situations.
I didn't think Oliver's father was all that harsh. He didn't say absolutely not. He just asked Oliver to wait. Considering how Oliver behaved, it was not unreasonable for his father to think, as Jenny suggested, that Oliver was going to marry Jenny to "get back" at his father.