One of my worst, and final freelance web development gigs was for a foot worship events website. Not porn - this was an event website featuring a calendar of upcoming foot worship parties/nights in London. I was a bit naive at the time and didn't really know what it was all about, or really anything about the BDSM scene for that matter. Definitely not kink-shaming here - everybody should be absolutely free to express their sexuality however they see fit as long as it is consensual and does not cause any actual harm - but I honestly felt really weirded out after doing it. It didn't pay well at all, and I needed the money.

The client was really flakey (bad choice of words perhaps) and late with responses and payments. The website was nothing special but was a bit of a bore to design and code.

I think it was the final nail (again, poor choice of words) for my freelancing career, and I went to join a startup which ended up working really well for me.