I'm a fairly new host and came upon this answer when I seemed to have gotten into this situation.
A guy with a good review came booking, at first for 3 ppl but then canceled because he said his third friend isn't coming anymore, and he would like to find somewhere with a budget for 2. Then shortly after, he came back and booked for 2 ppl. Because we have an extra people charge after 2, he discovered this and told me it would actually make a good deal for 2 ppl. They booked for 2 nights in the end.
This person was very polite and respecful during the booking process. As a first-time host, I didn't have many guests who came with previous reviews, and this guy has one good review, so I had confidence in him. Some days before check-in he asked me nicely whether he could have a few friends over to do a pre-drinking before heading to an event. I trusted his character and gave the okay. But stated explicitly "no partying, no heavy drinking and no staying overnight". His response was very satisfying.
After he checked-in, I texted him on the second night, asking what time would he want to check out the next day. He then told me he had a family emergency and had to leave the condo half-way, and that his other best friend was able to be there to keep his friend company! Wait, does this mean his 'other friend' stayed instead of him without my approval? I never get to find out.
What I found out after they checked out was that the place was covered in muddy footprints, food stains everywhere on the floor (even under the carpet), garbage full and an odor that couldn't be gotten rid of to this day. There were sticky stains on everything like bathroom sinks, bathroom switches, sofa pillows, which took a good amount of time to take off. I can't possibly believe that this was done by two guys in just two nights.
We have a two bedroom and a sofa bed. The sofa bed was clearly used because I can see the tag pulled out. Two extra comforters were pulled out as well. Why would two guys need to use three beds and four comforters is beyond me.
After I read your thread I believe what you said. There is a pattern here. I can't believe I didn't see this coming. Other hosts should be warned.
But now I hesitate to leave a bad review for this guy. Partly because he had a previous good review, and I'm just a new host without any reviews. If he were vindictive and leave a bad review for me, it would be the first review of my house. That doesn't look so good for a new listing, does it?