Notice that Mr. Bennett has "found" that Jane is crossed in love. I think, given what we know of Mrs. Bennett, that SHE is the one who informed (lamented about it at length to) Mr. Bennett.

One parent considers Jane's disappointment as the death knell for the daughter's happiness and the ruin of the family. She is never quiet on the subject, and tries to engage the uncomfortable child in frequent, irrational, and emotional discussion of it. The other parent may be doing everyone a favour, treating it a little light-heartedly, standing back and noting any saving humour that might be available. That MAY be the best opposition to counter the increase in pain brought on by the other!