And to clarify what I mean by "strictly monogamous": If you watch porn or think about having sex with someone else besides your SO you are not strictly monogamous. And no, I wouldn't consider those two things as cheating but the fact that you desire sex from someone or something else besides your SO means that your libido is naturally polyamorous.
In the case of the former, my partners aren't usually fucking machines like I am and don't want to have sex when I do sometimes and I'd rather use porn and jerk it than pressure them into being a fucking dildo with a cardiovascular system like I am.

Plus it means I can last even longer when they actually are dtf later that day.

I love the way people flip out about cheating by the way. I don't think it's ever phased me, though it's only ever happened with relationships I wasn't really that invested in.
e: I was actually invested in one once, now that I think about it. The "I love you but I'm not in love with you" shit I always fucking hear was a lot easier to take when it was accompanied by my partner finding their "soul mate" (who left them later, sadly).