[Epona]

Yorick, I am a firm believer that problems for a couple do not originate from outside the relationship, but from within it. Existing problems can be highlighted by outside events and third parties, but are in no way the cause of those problems.

As you have seen from the responses on this thread, people with secure loving relationships based on trust take it as a compliment - people with existing problems can become insecure, or realise that better is to be had elsewhere.

If your friend felt insecure when you complimented his partner it is not your fault but a sign for him that he needs to look closely at his relationship, and either try to repair it in some way, or if that is not possible say goodbye, sad as that may be.