The phrase "Republican Logic" is an oxymoron. (Look it up if you need to.) Their "logic" is simply self-serving rules made up on a case-by-case basis to serve their own ends, regardless of the logic behind their thinking.
Strategies that can prevent getting STIs are abstinence, and proper use of female and male condoms. Situations that increase chances of getting STIs are putting yourself in a private situation without protection, or under the influence of drugs and alcohol.