Sex

[Assertn]

There are plenty of couples that maintain healthy relationships are also frequently involved in threesomes or different partners.

My girlfriend has told me that as long as I told her beforehand, and that as long as it was for the benefit of our relationship, she wouldn't mind me sleeping with other people.

I think if you were ever inclined to sleep with another person in the first place, openness would be beneficial to your relationship, considering the alternative would be to do it anyway and just build up deceit and resentment within the couple.

In other words, she might be hoping you'll let her sleep with other people openly as well. It could become a hurdle for you guys in the future if you deny her that