Fred understood that Weiss wasn't always great at showing affection. But he also knew that she loved him, so when she acted less than affectionate, he understood. He had been raised differently than she was, so his ability to be affectionate was different than hers. He loved her, he would do anything for her. He didn't mind that she wasn't always affectionate.
He gasped at her words, "I most certainly do not!" He grinned at her, knowing she was just teasing him. He liked it when she teased him. Because that made it so he could tease her. Something which he did quite often.
He leaned in and kissed her once more. "I just... I wasn't supposed to turn 22, so it makes me feel old."