My best man got married without telling me

I’m getting married in 5 weeks time.

My best man got married last wkd, without telling me anything about it. One of my ushers & wife were there for the celebrations. Both kept everything secret from me, as if I’d never find out.
My best man- been a best mate for nearly 40 yrs.My usher ‘friend,- also a best mate for nearly 20’odd years.
Why they did this, no explanation.
Is this acceptable???