Loving sex, when two partners are expressing emotion, is probably always best when two-way.
Three-way sex is for sensual pleasure alone, not emotional. It's a sexual adventure of sorts, part of the excitement wondering how you'll handle it. One's preference for three-way sex is an individual decision, with no necessarily right or wrong answer. From what I understand, some women like having two men attending to her needs. Probably, quite a few people have experimented with it at some time in their life. Few seem to carry on with it for very long. And, remember the saying: when sex in a relationship gets messed up, the relationship itself is then is deep trouble.