
Yes! They definitely do, especially if they are a genuinely caring person (at least toward the one they love). It's just been implanted in our minds that if there are no outward expressions of love (like cuddling, holding hands, blushing, smiling at each other, etc), then there is no love at all, which isn't the right sort of message at all. Not all people explicitly express their love like that.

I think mangaka meant to pull a kdrama male protag on us with suhyeok.. male leads in kdrama often come off as cold, but they still express their love through their actions.. i think suhyeok has been nothing but sweet to seunghee, but its would be even better if we get to hear something on his part too
Trust me, I am so happy that Sunghee and Suhyeok got together because I was always rooting for them. It's just that I am so used to reading yaoi/shounen ai where both of the characters thoughts and feelings are explicitly conveyed that Suhyeok not showing much lovey-dovey emotion toward Sunghee (i.e. blushing, being super happy, etc) is throwing me off guard. I know of course that you don't have to do these things to be in love, it's just that I got so used to that being the pattern in other yaoi/shounen ai that it's off-putting and slightly concerning.