So Newt hooked up with Percy before he left America. And then somehow when he comes back they just fall together and have really great sex, etc. Percy gets to know Newt's creatures, etc. They have a nice few days and part in peace and rinse, repeat the next time Newt is in town.

And then after the fourth, fifth time they do this, suddenly Newt arrives in America and is just irrationally happy about seeing Percy and they have marathon sex as usual but Newt is all omg i am having feels and is starting to be sad because he thinks Percy doesn't feel about him the same way

and then angst and woe and

tina or jacob or seraphina is like u guise pls

and then happily ever after.