It wasn't a no because he didn't want sex and was being force to do it, he definitely wanted it, he even said yes in the beginning when his friend offered, the yes became a no after he found out the dude didn't own a condom. I guess because it was quite messy with no condom, and health risk he didn't want penetration. Although he got over quite quickly when the dude penetrated him, i would be more worried if he kept saying "no" the whole entire time he kept trusting, and was scared and crying. For some Yaoi manga's, the actions speak louder than words, i've seen so many ukes in manga go "no, no, no" out of embarrassment, not because their are being forced and it gets annoying sometimes. It was honesty consensual for both parties, im pretty sure if the dude had a condom he wouldn't have said no towards the sex.
i was kinda icky about this chapters bc he kept saying no, but ginu kept going anyways
and i guess he did enjoy it, but consent??? is important y'all???