SUBREDDIT: r/relationships
TITLE: My [24M] Boyfriend [26M] of a year has brought up some ideas of an open relationship, and now I'm scared he'll cheat on me
POST: So I met *Ben* about a year ago through friends. Cue normal relationship. But recently he has been talking about a situation where we sleep with other people, whether that be together or apart.

Now the thing is I'm not really the open relationship kind of guy. Its happened before and I really didn't like it, it ended a previous relationship.

But the problem is how I said no. I gave him a soft yes initially but then after thinking about it I really didn't like the idea. I started dropping subtle hints that maybe I wasn't into it before giving him an outright no last week. He looked hurt and annoyed, but said he was fine with it.

Now I am really scared he is just going to end it, or worse string me along and then end it by cheating. I don't know what to do.
TL;DR: 
BF wants to make our relationship more open, I said no badly and now I'm scared he is going to cheat on me or end it.