Generally speaking you should be yourself and be able to say whatever you want when you’re in a relationship. But exercise caution and never find yourself uttering these lines if you don’t want to end up in the doghouse:
1.“My ex always used to do __________”. They don’t want to hear about how your ex used to cook for you all the time. Or how they worked out every day. Or anything about them at all, really.
2.“You’re like a brother/sister to me”. Major romance killer. You are not siblings, so steer clear of any familial comparisons.
3.“Why can’t you be more like ________?” Don’t compare your partner to someone else or expect him or her to live up to someone else’s standards. No one wants to hear that you think someone else is doing something better than they are.