Musar על ערכין 31:2

But there are times when the Sages permitted one to lie, for example, in order to make peace between one man and another (Yebamoth 65b). Similarly, one may praise a bride in the presence of the bridegroom and say that she is lovely and charming, even though she really is not (Kethuboth 17a). A guest (Arakin 16a) who has been well treated by the master of the house should not to say in front of many people, "How good that man is in whose house I was a guest, how much honor he paid me," lest many come to that host who are not worthy to be his guests, and concerning this it is said, "He that blesseth his friend with a loud voice, rising early in the morning, it shall be counted as a curse to him" (Prov. 27:14).