Possible Sources of Coolant in Oil?

I know this sounds crazy,,,,,but what kind of oil are you using .
Years ago,,,,I decided to use some ultra cheap stuff for my daily driver truck,,,,you know,,,,what could it hurt to try .

The oil turned red after a few heat cycles,,,,,looked like pure rust mixed with blood,,,,scared me to death almost .
Drained it,,,,went back to normal stuff,,,,no more weird colors .

The reason I say this is because you aren’t losing water,,,,,and I’ve never seen oil and antifreeze mix like yours .

Tommy