2. Work Hours Change
If your partner is working late or putting in more work hours than usual, maybe something other than work is going on.
Working late is a good excuse to be away from home for several hours at a time.
Working late does not always constitute cheating, but it does mean you need to pay attention to see if what is happening may be detrimental to your relationship.
It could be as simple as not wanting to come home to a nagging mate.
Give them something to look forward to when coming. Make their favorite dinner or plan an intimate date night.
Change up the normal process and make it interesting. Run a bath and give them a massage some evenings.