Betty's reaction was actually not unexpected from Aria.
Calvin was indifferent to Betty and had forced her to have abortion.
These add up to enough to break a woman's heart, even if this woman has now forgotten everything in the past, from the description of people around her, Betty would not have much good feeling towards Calvin.
So it was only normal that Betty didn't believe that Calvin was now in love with her and wanted to be with her.
"Well, Calvin has not yet officially confessed to you, you can pretend that you are not aware of that." Aria shrugged her shoulders.
Betty did not reply.
Aria was not angry, but said with a smile: "And Betty, if after that Calvin really confesses to you, will you..."
"I won't agree to it!" Betty replied without hesitation.
Aria blinked, "Why?"