I’m not sure exactly what your question is either. The wording of the question is kind of confusing and it seems like there is more going on here, than just asking about what “in like” means. But I’ll give it a shot.
Generally, when someone says they are “in like” with a person, it means that they are on the road to falling in love, but it’s just the very beginning stage.
You said that you still have deep feelings for your ex, and the last time that you told your ex that you “couldn’t handle it” when he said he had feelings for someone else, your ex broke it off with his new girlfriend. I see a few problems here.
Not sure why you and your fiance broke up. If he broke up with you, because he didn’t love you or want to marry you, then you probably shouldn’t even attempt to be friends with him now, after the fact, because it will always be too painful for you and you will always subconsciously be trying to win him back, even if it means that you sabotage his other relationships.
If you broke up with him, what was your reason? Again, you probably shouldn’t remain this close of friends with him after the fact, because it’s kind of like you are “playing house” with him and will always be in the way of any future relationship he might try to form with someone else, because he doesn’t want to hurt your feelings, so he dumps the new people.
You and your ex need to figure out NOW, if you’re meant to be together as a couple. In the meantime, you should cool it with your current boyfriend, and let him know that you need to figure this thing out, if you stay with the current boyfriend while you are figuring it out (or don’t tell him what’s going on) it’s not fair to him at all. Your current boyfriend deserves to have someone that loves him and wants to be with him, only, not have someone that really loves another guy much more. How awful.
If you are pretty certain, that you and your ex are not meant to be together, then step back from this relationship, because right now, you are kind of creating a threesome, where there should only be a two-some. If I was the woman who your ex is dating right now, and I found out that you were still interested in him, I’d be pretty upset and want you to back away from my boyfriend.
It sounds like you and the ex need to do some soul searching, but make sure that all of the other parties involved (your boyfriend and his current lady friend) know what is going on too.