The fact that you believe that casual sex affects pair bonding ability at the chemical level, but you don't believe that condoms prevent the spread of STIs and pregnancies is concerning.

Not all STD's need to contact a mucous membrane to infect

Condoms (and other forms of birth control or protection) seem much more effective than conservative morals at preventing diseases and unwanted children. Take a look at teen birth rate [1] (as a proxy for unwanted or at least unplanned pregancies) and HIV diagnosis rates [2] per US state. The trend seems pretty clear: conservative, religious states do worse at these metrics than liberal, more secular states. There are of course more variables than that, but at least religion and traditional family values don't seem to be helping very much.

[1] https://www.cdc.gov/nchs/pressroom/sosmap/teen-births/teenbi... [2] https://www.statista.com/statistics/257734/us-states-with-hi...

There is a 100% guaranteed way to prevent an unwanted child, in half of the US states at the very least.