So, problematic in this scenario doesn’t necessarily mean *a problem.* It’s more that it’s a situation that should be handled delicately.

A lot of unicorn-hunting is a male-female coupling (ie Sir and I) looking for a single girl down to have a threesome (which is, yeah, our situation.) Commonly, the interests and needs of that third party are set aside for the interests and needs of the couple. 

The whole process of unicorn-hunting is inherently selfish. Essentially, it’s two people with a deep, pre-existing relationship looking for a third person to enter into that dynamic for the sexual gratification of those two people (and ideally the third person as well) without any of the emotional gratification of the relationship. People who end up unicorning can end up being fetishized (couples that want to fuck a girl of a particular race are disgustingly common and incredibly problematic) or just feeling used (metaphorically or even literally being kicked out of the bed immediately after the encounter.)

When you’re out to have a threesome like that, you’ve got to be mindful of the needs and expectations of that third party. You need to be up-front and honest. You need to be respectful of that person’s feelings and triggers. And a lot of the time, people are – often unintentionally and without a hint of police – still a little insensitive to those things.

I’d honestly prefer a kind of sister sub scenario if I’m talking about ideals here. But that also can be a whole can of worms.