Oh for pete's sake. This single incident in your otherwise good marriage is not cause for dramatic action. Tell him you want to go get some coffee with him, be reasonable and firm - but not defensive and angry - and really listen to why he wants to go on a 4-day stag. 4 days is excessive. It sounds like he's aware of that, and defensive about it. Talk it out, be a mature couple. Best to you...I believe that this can be worked out.