4. Calling his female friends out of nowhere because she suspects he’s cheating
“It causes trouble for my friends, and more than that, it’s incredibly embarrassing.” Having their girlfriends butt into their other relationships and mess things up is an uncomfortable feeling for a lot of guys. Plus, even if he is cheating, that’s something for the two of you to work out on your own. Even if you’re concerned he’s cheating, calling the girl you think he’s involved with is definitely best avoided.