I messed up

So I’ve been dating this guy for 2 month it’s clear that we want to be together we are just taking it slow. Last night I went out for drinks and I slept with another guy but I was so drunk I didn’t mean too. The guy I’m talking to now has slight trust issues and he trust me if I tell him I might ruin everything. Do I hold on to this secret, and continue to feel guilty or do I tell him and risk it all ?