These are all excuses for not committing to a marriage covenant. These are classics... the best way to combat them is to EXPOSE their falsity... if you are speaking to mutual friends tell them outright... "sure I want you two to be happy to, but if one of you starts lying and cheating behind the other's back, I am NOT going to support that, its NOT happiness you are pursuing when you cheat, its excitement"...
many people confuse excitement for happiness... this is the case here..
