Gay threesome

Me (M21) and my boyfriend (M23) have been together for a year. Recently we’ve been considering doing a threesome. My boyfriend is a top and we would find another top to do it with us. Next week we’re going on a trip to another country and we are thinking about goin to a cruising club to do so. Have you ever had a threesome with your partner and would you recommend doing so? We both wanna try but im a little bit scared that it will change something between us. We’ve been exclusive the whole relationship but having sex with another guy we don’t know from a different country doesn’t seem like a bad idea. Can someone tell their experience?