Thats terrible advice...you need to be open and talk about things. If you want to tell someone something and talk to them to feel better, do it. If that sours the relationship you shouldn't be together, either way. Not talking will just rot the whole thing from the inside as you repress and feel bad instead of talking about issues which your partner SHOULD know. Never assume your on the same page about things, always make it clear and talk about it.
COMMUNICATION IS VITAL TO ANY RELATIONSHIP, ROMANTIC OR NOT.