[vidarh]

People have a risk level they're comfortable with, and sometimes people feel added excitement pushing right up to or past that level, and sometimes they're just happy to pay extra for something they feel is within that risk level if they enjoy it more.

We all choose to take risks all the time and often pay for the privilege, sometimes explicitly seeking out the thrill of a risk.

I'm guessing what makes this specific scenario weird for you is more likely that this risk doesn't seem worthwhile to you relative to what you get from it (and I agree with that - I've never had an appetite for taking risks with STDs)