“I do think if its important to your spouse, you should do it, even if you don’t think its a big deal. This goes both ways”
Most important point of all. But also IMO, even if you personally do not consider it a big deal, since many people do, it should be done as a show of good manners. if your mother-in-law were getting in the car, the son-in-law would not open the door for her???? Kovod should be shown to all people.