Safety First summary:

Tae-ho is in charge of Sejun, a newbie at the construction site. Tae-ho warns him to be careful because the site is dangerous, he's worried about the strangely over-eager Sejun. To top it off, he is burdened by Sejun, who keeps sniffing him and following him around- No way... is he fully aware and doing it on purpose...? "but Hyung... Are you in heat?"