Should I tell my friends and mentor that I was laid off?

I relocated to a different country and was laid off just after one month. Fortunately I got a job back in London. I will be catching up with some friends from university and some colleagues from previous firm. One colleague is like a mentor and I feel like telling him. But most likely he might share this news with my ex-boss who is his really good friend. My ex-boss is a veteran in industry. Its not like he will give a bad reference check in future but I am a bit hesitant. I want to share this fucked up experience but the energy trading industry is very small and I fear that ppl will know and that could harm my image. If you were me then what would you do?