That is so true, just look at the various women Cheryl Cole was cheated on for.
Basically, if a guy is going to cheat he’ll do it regardless of whether you look your best or not. If the intention is there in his heart it doesn’t matter how you look. That’s why a relationship needs to go beyond physical attraction, it won’t last if that’s all the relationship has going for it.
That being said if I look after myself I’d expect him to do so as well 
No beer guts for me thanks.