If you're asking if a married person in PA will be criminally punished for having sex with someone other than his/her spouse, then the answer is no.
To be honest, even in states where it is still illegal (such as Maryland, for example), the punishment is quite light. If I recall correctly, it's a $10 fine. The purpose of keeping it illegal in Maryland is not to punish the offender, but to allow him to avoid testifying about it in a divorce
case (in other words, a person cannot be compelled to incriminate himself, and thus, he can refuse to answer a question about adultery in a divorce case). That keeps the burden of proof on the spouse claiming adultery.
I hope that helps.
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