Well, the constitution says parents, not parent. There is a lot of corruption in politics, in case you hadn’t noticed. So you would be ok with a foreign government official having a child with an American and that child running for POTUS?
Let me guess...you've never actually read the Constitution, have you? It says no such thing. This is the entirety of what it says about presidential qualifications:
"No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States."
Do you see the word "parent" or "parents" in there anywhere? Of course you don't.
Nope, the constitution does NOT say “parents”. It’s not hard to do research on this issue.