CO, I am not at all familiar with the heroin users and the issues that arise of heroine use in the present or in the past, but just common sense tells me that the double life and disappearing might also be related to a potential resurgence in the use of drugs. Disappearing does not have to mean that he is seeing another woman. Heroin and other hard drugs that you mentioned later in the thread are serious drugs and the possibility of his resuming their use is at least a potentiality, especially if he is unhappy and seeks a flight away from his reality.

The divorced male worker might be seriously interested in you romantically, but to hide his interest from you and possibly even from himself, he makes a point of praising you for something that cannot be construed to mean that he has such romantic interest in you. This is by no means certain, but, like resumption of heroin use by your H, it is a potentially that cannot be dismissed. That the coworker's praise struck you as odd may not be due the fact that conversation is lacking inside your marriage; rather, your coworker might have been sounding unnatural in what he was saying (see above), and you picked up on non-verbal signals that manifested his being unnatural and that struck you as odd. It is impossible to say for sure - I am just offering different explanations as, again, mere potentialities.