“Let no evil talk come out of your mouths, but only such as is good for edifying, as fits the occasion, that it may impart grace to those who hear.” (Eph. 4:29)
“But now put them all away: anger, wrath, malice, slander, and foul talk from your mouth.” (Col. 3:8)
“Let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer every one.” (Col. 4:6)
“And the tongue is a fire. The tongue is an unrighteous world among our members, staining the whole body, setting on fire the cycle of nature, and set on fire by hell. … From the same mouth come blessing and cursing. My brethren, this ought not to be so.” (James 3:6, 10)
You should avoid using vulgar language. Even when you’re out “with the boys”.