<human>: My boyfriend and I have been together for 5 years and we are in a very loving and supportive relationship. We are very open about communicating with each other whenever we have problems. We started dating in college and he was my first for everything but he had a gf before me so he has a bit more experience than me. Earlier this year my bf expressed interest in bringing variety into our sex life. We have a really good sex life but after being together for 5 years sometimes it is nice to try something new. He wanted to go to a sex club or even have a threesome. I am not comfortable with having a threesome with a girl so he was even fine with having a mfm. I basically have only been with one guy so I'm also interested in trying out what it is like to see other people. We seriously love each other and will probably get married in the later future but is it going to hurt our relationship if we try and experiment with other people? I am scared that one day we will regret not experimenting with different people when we were young and always wonder what it would have been like. I am also scared that if we go through with it that one of us might freak out and back out (likely to be me since I am a female and I'm slightly more prone to be jealous). 

Basically I would like to know about any success stories or failures from redditors who tried to have an "open relationship". We are young so we are just interested in opening up the relationship just for sex.

Summarize the given text in a few sentences.
<bot>: bf and I are in a great relationship but after 5 years we want to try to have sex with other people since we only have had each other. Will this work out or is it going to crash and burn?