This might sound counter-intuitive, but boundaries are integral to love. It's about saying "yes" when we mean "yes" and saying "no" when we mean "no". It would be nice if people actually used authentic yes's and no's because then we'd actually know who they truly are.
Thus, in loving my spouse, I allow him or her to truly know my likes, dislikes, tastes, desires, and in the extreme, what I will not say yes to. My boundaries invite my spouse to see who I truly am, and this is one of the greatest aspects of love, which is to know and be known.
The other week, I asked Sara if she'd consider doing something for me. I can't even remember what it was, but what I do know is that she was very clear that her answer was "no". I'm a lover of boundaries, but even for me, it was very difficult. In the end, I have to deal with her yes's and no's, and her boundaries help me to know her heart, mind, and being. This is one of the greatest aspects of loving our spouses despite the discomfort. Knowing my partner's boundaries establishes trust through a baseline of predictability and connection.
Notice in the photo that I've chosen a gate to represent our boundaries. Boundaries are not walls, rather they are like a gate which you can come in and out of with permission (Cloud & Townsend in Boundaries). If you don't have permission, then the gate stays closed, but if you do have permission, then the gate is open and you can come on in. Our gates are weaker or stronger depending upon the level of trust we have with the other person.
In the end, boundaries are about inviting others into relationship with who we truly are, which is a very loving act. That isn't selfish. That's being outward focused.
(photo taken from flickr creative commons by authentic eccentric)