"At a mixer, the guys have to work hard to liven things up."
"At a mixer, the guys have to work hard to liven things up. " "at a mixer" 「合コンは頑」"combined party" や "party" または "Gokon" も言えます。 "the guys" 「男が」"the men" や "the boys" も言えます。 "have to work hard to ~" 「頑張って〜ないとダメ」 "liven things up" 「盛り上げ」"liven up the party" や "liven up the mood."