Having multiply partners

Do you think that it is important to have had several sexual partners in your life time? I was talking with friends the other day about this and they felt that when you have only known one partner sexually that it is so romantic, I disagree. My husband and I have only had each other EVER and we are both wondering what we are missing out on, my friends believe that if we have sex with other people then we will be ruining the special relationship that we have! I know for me that I need more spice, I am wanting to experiment more in the MMF scene husband is a bit more reserved so looks like I will be doing this without him (which he is ok with) the whole BDSM really excites me probably because I am such a dominant personality I like the idea of someone else being dominant sexually. My husband is really a gentle personality and this scene sort of perplexes him. So have any of you had a life like we have had, really naive with latent sexual maturity (for lack of a better description) and then realised what turns you on and have just gone for it?