Why Was I D&D'd so Fast?

I think this is the one thing I can't let go of. It's the one mystery that keeps my stuck. Most folks on this site were with their Narcs for years or months before the mask came off.

N chased me for a month long distance. It was intense and fast with love bombing, talk the future etc. We had an amazing night when he finally came to visit (although it was all about the physical to him, and NOT getting to know me in hindsight). We kissed for hours in a park at night, then went back to his hotel room (we did things but I didn't go all the way with him, because I wasn't ready to).

The next morning, I explained that I thought things were moving along physically too fast for me and could we slow it down and get to know him better. Mask came off and he was distant, cold, said he wanted to 'run away from me'. He was never romantic again over the next few weeks. Talk of the future, gone. I was just a buddy. So I broke it off several times (I returned twice because I couldn't stand it), only to be treated the same.

Why was he so intense then uninterested so fast? Why didn't he keep his mask on for months or years like other Narcs? Is it because I wanted to move slowly sexually and he didn't like that?

When he changed I accused him of using me, and the uninterested guy turned into cold, cruel guy with silent treatment.

He said I had issues with sex just because I wouldn't sleep with a guy I only knew for a month online/through the phone (not in person)!! This coming from a cheater who obviously can't keep it in his pants (he told me stories of cheating on his ex wife when they were married, after his mask came off).

Same background of other Narcs. Has ex wife, and girlfriend with whom he said he's no longer in love. They're just room mates blah blah blah. Two kids with ex, two kids with gf.

It hurts that he tricked me like this. I adored him so much. It was so fast an brutal....