This dream sounds like it is chock full of trust issues. First you don't trust your own choice because you don't know who you're marrying, then you are asking your ex not to lie anymore, showing regret for the breakup but that you know you can't trust him. Then there is your current bf with the 2 girls. I think you might not be feeling solid ground beneath your feet. You have a deep down fear of being hurt; quite possibly by your own choices.
So ask yourself if there is a reason to not be trusting your current bf or if this is a personal issue that you need to face. Just a hunch. Hope the advice helped.