Yes, but make sure you're actually telling the truth as well. If you say you won't be going directly back home and it's a lie, it's worse than just saying "sorry, not today"

I feel like this opens it up for questioning, if you say you're going elsewhere they might ask where - the implication is that you would drop them off if not for the fact that you weren't going straight home. The response might be something like "Oh, you're going to those shops? I need to grab some stuff too, I'll come along." and now you've just roped yourself into a longer trip

@LioElbammalf that's why you don't tell them you're going to a shop, you say you're paying your parents a visit, meeting with your partner for a bite in a restaurant or something else to which they can't just invite themselves along. It still has a potential for trouble though, if you tell them you're going in opposite direction and then they see you on their way home it will look worse than if you just told them no without a reason

@AnnaAG Absolutely, but it requires expanding on the lie. I'm just saying there is no reason to expand, can only get yourself tied in knots. Just tell them you can't without any reason given - you don't owe them an explanation.

@OmarL Lying is not always bad. It's a lesson you learn usually by the age of 10 years old.

@GregoryCurrie A white lie here and there is one thing, but telling lies about things you don't need to lie about, and then getting found out, that's a great way to make people think you're an untrustworthy fool. Or of course it could backfire as well; imagine this: "Oh you're doing groceries on the way home from work? Sure I'll tag along! I need to pick up some pocky anyway. And you can listen to my sales pitch as well! It's an app which is like uber but for snacks. We could make millions!"

@OmarL Why give detail. Just say you have plans. Give them a chance to take the hint.

This is not "social grease". This is lying. There is nothing to be gained with this lie, except a reputation of being a liar. You don't need lies to justify saying "no" to someone who asks for a ride.

@Stef sometimes social grease is lying, and both sides know it's a lie, but it's the politer option.

@Kilisi : How would they possibly know it's a lie in this case? They wouldn't. There is absolutely nothing polite about lying like that, and no reason to do it in the first place. Why are you so afraid to say no that you have to lie about it?

@Stef "This is lying". It depends on the country you live in whether or not this kind of lie is actually something bad. In countries like Italy such "white lies" are quite common and are a socially acceptable way to refuse to do something instead of giving a blunt "no" without explanation. You don't need to give explanations, but in some countries this is considered rude, as it is rude to not catch the hint and still "rise the bet" like "oh, you are shopping, I need go shopping too, I'll tag along"....

@Stef I would be highly offended by a colleague calling/considering me a liar because I responded to him with an excuse just to be polite to him. Social conventions are highly country-specific and we don't know anything about the country of the OP, so we should assume nothing, although I get some "western country vibe" I couldn't place him in the USA or in some European country, where these social conventions vary wildly, especially between southern "latin" countries (e.g. Spain, France, Italy) and more Nordic countries (e.g Germany, the Netherlands, UK, etc.).

Sure, be highly offended because someone considers you a liar after you lied to their face.

@Stef Consider if you do say "No" to your colleague and they respond with "Why?". You basically have two options, tell them bluntly that you don't want to spend that time with them or lie about having to do something. At this point the best of the two options is to just make up an excuse, at which point you may as well have done it from the beginning and saved time and effort. Hence why it has become a socially accepted norm in some cultures. Also, it can be a somewhat more polite response, as it implies that it is not the fault of the person, but again, it depends on culture.

@Stef Please, before judging someone, try to learn that different cultures treat social interactions differently. Social conventions are extremely country- or even region-specific. Even if we could agree to what can be considered a lie ("not telling the objective truth"), in some cultures it could be highly offensive to be asked something that warrants a lie as an answer.

@Stef Social interactions are not trials before a judge. There is no universal right to get an answer to any question one may ask. If you ask me something I don't want to answer because I find it an intrusion of my privacy, lying is in my right without being called a liar, as absurd this may sound to you. In some cultures these "non-truths" are not considered "lies", and calling someone a liar because of them can get you into big troubles socially (and sometimes even before a court).

@stef If you want to improve your knowledge on cultural differences you could read this book (The Culture Map - Eryn Meyer). It's enlightening and could avoid you fatal blunders in social interactions involving people from different cultures.

@LorenzoDonatisupportUkraine Thanks for the recommendation. It so happens that I had already read it. I find it sad that it can be misinterpreted to the extreme point of using "different cultures" as an excuse for lies. Especially in a situation where lying is so useless like this one. Have a good day.

What if they ask again the next day, and the day after that? If OP is uncomfortable with the idea on principle, they shouldn't have to come up with a new excuse each time, hoping the asker will get the hint.

@Llewellyn then they are the ones who are socially inept. Just repeat the excuse. They should have worked it out already but a second time should be enough.

@Stef if it worries you so much, it's not a lie. No one goes straight home unless they live next door or they'e a bird. We follow convoluted paths along roads etc,.