Authors in-ability to create changing character is so frustrating. Like any shyness and embarrassment goes away after doing something multiple times. Like going for a date the first 1st will make you awkward after that first time shyness will decrease substantially and this goes for other things too.
They've known each other for quite a while already yet he still acts shy, awkward and perverted (as if he saw her for the first time, dude saw her in bikini for crying it loud). It's not character growth even, it's basic HUMAN PSYCHOLOGY and authors fucking inability to show this is remarkable.