Feel bad for Shelby
Morgan did a Periscope recently alongside sister Alex, Monte, and her roommate. Later, Shelby joined them via telephone. As they answered fan questions live, some of the comments suggested Monte and Shelby date, to which Shelby responded that he would just ghost her like every other guy (she had previously brought this up and said that it was really just one guy, and it was someone they all knew). Around 1:26:00, Morgan decided to "take a poll" asking whether Monte and Shelby should date. A lot of people responded in the affirmative but there were also many comments shipping Paul (BB18) and Shelby. This isn't something new as the fans had started shipping them since the season ended when the two had hung out at the post-OTT party and interacted with each other on social media. But while she had been open to it before, in this case, Shelby basically made it known that she "didn't like" the responses suggesting she date Paul and expressed her disgust. It was very awkward since Morgan, Alex, and Monte obviously knew who she was talking about but they didn't want to mention him by name so they began to ignore/tiptoe around any further comments mentioning Paul or demanding to know what happened.
Of course, we don't know the details but it's very likely Paul did do this, which is unfortunate. He held an AMA ("Ask Me Anything") session on the Big Brother Reddit not long after but avoided answering any questions on what happened between him and Shelby.
Morgan's Periscope can be viewed here: https://www.periscope.tv/morgan_willett/1dRKZXgjoMdJB?