@Sarinya *********

There is no ban if caught at the airport for less than 90 days overstay. A 5 years ban while leaving Thailand is for a 3-years overstay. Your friend is not telling you everything, but it doesn't matter. The 5 years ban is over, he should be able to come to Thailand.

Yes, I know the law. The left side of the picture is always enforced, but not the right side. To get the 5 years for 2 weeks overstay there must be more to the story. It would be like getting jail time for ecigs.

I have never heard of anyone ban for 2 weeks' overstays, let alone 5 years. Your friend is not telling the full story.

@Frank-Steven **********

You do not need a visa to border run. In your OP you mention not entering the 2nd country and staying in no-man land, which doesn't mean that the only alternative is to get a visa beforehand. I'm Canadian and I do not need a visa to enter Laos, Cambodia, and Malaysia. I can get a visa-exempt or visa on arrival or wtv the name is directly at the border upon entering. The process is very quick. Then you turn around and go back into Thailand. In Laos, you can go in and come back to Thailand within an hour. If one hour is too much I don't know what to tell you. The whole process is no longer than entering Myanmar with that 500 baht piece of paper.

You seem to think that avoiding a stamp = fewer restrictions, which I don't think are related. If you are unvaccinated and looking for a quick border run, I don't think it will be possible anywhere for a while.

@Frank-Steven **********

I have no idea of post-Covid restrictions, nor about motorcycles.

If you enter Tachileik via Mae Sai, no visa is needed if you stay in Tachileik province.

Yep, this is how I was doing border run pre-covid. You do not need to stay overnight.

An affidavit that you are legally free to marry.

OP documents are in English = he cannot get married.