first of all, note that this guy hasn't formally talked the love talk. according to the OP, what he has said is "you know you love me" and other statements to that effect. please keep this in mind as i move through the rest of this post, as i think it's an important detail.
so... why would someone manipulate a significant other in this fashion?
the two quotes above offer a good starting point to one of many possible explanations. i'm venturing into very speculative territory by responding this time around, so i'll just describe what it was like for me when i used to behave this way.
in every relationship, there is always a person who cares more and a person who cares less. i was always careful to set myself up in the dynamic as the person who cared less. all of the control lies in the hands of the person who cares less; if/when it all fell apart, i didn't stand to lose nearly as much. i wasn't invested. i wasn't vulnerable. i wasn't connected on any meaningful level. i refused to give my heart away, and this meant it could never be broken.
at its core, i assume this stems from a fear of intimacy - real, genuine, raw intimacy. this is also why i was able to detach emotion from sex so easily even though this is a privilege that is typically reserved for males. if you don't allow yourself to care on any level but the superficial, sex becomes just another act. a fun act, sure, but mostly a utilitarian practice.
the rub here is that no partner likes to be made acutely aware of the fact that they are the person who cares less. you don't want your significant other to know that if push came to shove you could take them or leave them (probably leave) and most likely escape unscathed. that's not to say that i didn't like any of my exes. a lot of them were immensely fun, super hot, good to have around in social situations, or fed my ego, kept me company, or otherwise amused me. i liked some of them quite a bit - certainly enough to want to keep them around - but not enough to drop my defenses or address my hang-ups entirely.
i guess the simple explanation is that i liked the people i dated, but i didn't love them, and moreover, in my heart i wasn't even open to the idea of loving them. i loved my friends, and they came first. boyfriends? those guys come and go. my loyalties were to myself and to a small inner circle of close childhood friends. everyone else was just a guest in our world.
the game here is that you have to always give your current partner the impression that they are slowly being brought into the fold, welcomed into that secret society... you know, by virtue of their specialness and awesomeness. you dangle carrots. you throw them scraps of time and affection at your own leisure, making sure that it's in the right amount and frequency to keep them coming back for more. you only have to play a few people like this before it becomes a habit and you kind of stop thinking about it. keeping people at arm's length just feels like the natural amount of distance. any push for more is met with accusations of being too clingy, too jealous, too needy, paranoid, immature.
god, this is fucking embarrassing to type out.
i used to feel smothered all the time by pretty much everyone i dated. i wondered why i attracted so many attention starved babies. as it turns out, all these people wanted was an adult relationship. equality. priority. respect. in hindsight it's obvious that i had no business in the dating pool, but i liked having hotties around so i did the bare minimum to keep everyone pacified. you can gift wrap the bare minimum in a lot of shiny looking faux-compromise and measured self-disclosure and smiles and sex if you want to keep someone around. it's not always so sinister and intentional either... it's just the behavior of an emotionally stunted individual who isn't ready to fall in love.