i think this is a fair point. one may yet resist the charge by saying, one must by caring, as the first limb of my account, naturally consider fidelity. but i shall resist this temptation. this is a very fair point, and must be very fairly considered.
i remember a passage in norwegian wood which had reiko explaining to toru that loving two women at once was okay. it goes like this:
"things like that happen all the time in this great big world of ours. it's like taking a boat out on a beautiful lake on a beautiful day and thinking both the sky and the lake are beautiful."
i believe that's true. i mean, people do lose their spouses. and they do fall in love again, and they do get married again. this may be a bit of my inner libertarian tendency coming through, but i believe that love is a wonderful thing that can be had at any time in any place (and almost, with any person). so the crux of it is then how we act according to the feeling of "love", i.e. of liking and then of caring. and fidelity at its most complete should, in my opinion, have very little to say about who we "love", but very much to say about how we act according to that "love". accordingly (and by god, woohoo!), my account of "love" is in a domain prior to and separate from that which fidelity is concerned with.
in fact i think norwegian wood explored the idea of loving two women at once beautifully, and to my mind, responsibly as well. but this is toru in a nutshell - midori told him that she loved him because he only acted when he felt sure of what he was doing.
so i have described spaghetti as flour and eggs (and seasoning). tomato is merely in the sauce. and who has not had, say, squid ink spaghetti? but i am partial to tomato too.
by the way, the following is, to my mind, the most accurate song about love i have ever heard in my life.
the darkness, love is only a feeling
https://www.youtube.com/watch?v=QSGa1dW_KoE