If the spell is to increase understanding and to enhance the connection between you and this other person, then I think that as long as you have sufficient focus and skill it shouldn't be too much of a problem.
If the spell is to try and control the other person or to change them then not only will the difficulty be much higher, but I would advise staying away from the spell all together. Forcing someone to do something is never a good idea nor is changing who they are through force. It can have very bad repercussions and odds are the relationship won't last under those circumstances because it isn't a true connection that is keeping you two together.
Best advice, avoid magic in the concerns of love unless it is for protection of those dear to you. Real love will keep two people together, no matter the circumstances.