You've closely described my own experiences, as well. I never had many sexual partners, but in my 20s I did have two that were nothing but an ego boost for myself...or perhaps more aptly, they gave me "approval" and made me "feel wanted" and special (even though I know, and knew THEN but I ignored reality, that I was no more special to them they were to me. And I liked these people well enough, they were decent men, but not men I'd ever truly develop feelings of love for. Yet I used them, and I still feel cheap and guilty and bad about it, even after all this time).
I had these and a couple other experiences pretty immediately after I was dumped by my first real boyfriend, whom I was with for 3 years. It devastated me. He moved on QUICKLY to other relationships, so I guess (well, I know) that I was seeking validation and comfort and desperately HOPING I'd find real love with another. But instead it was only playacting and sex that wasn't even enjoyable, and in the end, only regret and feeling like a POS for using another person for my own purposes. (the fact my father was always disapproving and critical and disconnected from me emotionally didn't help matters in regards to relationships w/men, either. just wanted to throw that in there as I think it's pertinent to this discussion and at least for me, was another reason I used men or attention from men to make myself 'feel better').
As others have said, when all is said and done, it's not worth it -- not to yourself, and certainly, definitely not to do to the other person who may have, or develop, actual feelings for you and then the hurt and pain is multiplied X times over.
I need to just stay alone. Luckily now I'm old, sick, and even more unattractive then ever so it's not a problem...