I thought Vicki a tad more responsive to Peter's kisses than she was to Burke #2. Then again, HE didn't seem to enjoy kissing her, while I bet Roger Davis tried to slip her the tongue, knowing him!
Vicki sure seemed upset over Burke's death, but I guess we have to give her the benefit of the doubt--going to 1795/6, which to her, at least, was four months, must have efficiently erased her feelings for Burke, especially after Peter stood by her and tried (inefficiently) to save her from the gallows. Perhaps she was just clinging to him as the only person there who was willing to help her.
Besides, didn't you get the impression that he thought her a little bit loose, and hoped that she was?
Love, Robin