Your question is NOT unreasonable, and NOT splitting hairs... because we use the term "love" SO MANY different ways. "I love you, Mom." "I love my kids." "I love chocolate." "I love it when Dallas doesn't make it to the playoffs"...
So perhaps your question is somewhat clarified by asking "what is the definition of marital love".
I was taught as a teen (in a church youth group-type setting) that that love in marriage is this: "love is a decision".
It sounds a bit cerebral or something, but I think I understood it at the time, and I think it is similar to the sentiments of WarpSpeed and SisterMilkshake. I took it to mean: if you base a marriage on the "romantic feelings" that modern culture calls love (that ushy-gushy heart-all-a-flutter sort of feeling) then you really risk your marriage falling apart when that feeling fades.
But if you can commit to "be there" and see things through when your spouse is having a crappy day, or YOU are having a crappy day, or when the bills pile up, or the kids puking all night, or whatever your challenges will be, then THAT is [marital] love.
As a wayward spouse, I left the affair (which had 1000% more "romantic love") and stuck with the marriage, owing to that notion that of "love is a decision".
I knew that if I had jumped ship -- leaving the marriage to be with my new [romantic] "love" -- that I would be killing something inside me. I would never trust that I wouldn't "jump ship" again when the next "more lovey-dovey" set of feeling came about for yet someone else.
So I don't know if that is helpful or not for you to think about.
In fact, if I were the betrayed spouse, I don't think my definition above would sound very comforting at all. It is almost saying "well, I don't feel THAT great about you, but, heck, I'll stick with it because I agreed to it some time ago."
Yet, for me it lead to the right decision for me of keeping my family together (for which I have confirmations every day).
Quick aside: even though my parents took it quite hard when I changed religions (while in college), I'm not sure they ever realized how much at least that one lesson took root, and is a substantial reason why I'm still married, and why their grandchildren do not live in a "broken home".