I've had a few that caused me to walk closer to the edge than my convictions said to go.
Relationships are very tough on the walk with God. Because someone can kinda conceal their true self, and then once emotionally attached, their true self comes out, and it's emotionally harder to end it or distance yourself from them. Or their dangerous side, meshes with our dangerous side, and hey, everyone likes to play with fire once in a while.
On the other hand, I don't necessarily think a relationship making you less focused is evil. Even Paul says married people have more cares, and can't attend to the relationship with God with as much focus. This isn't listed as a sin, it's just the natural outcome of being in relationship. So I guess at that point someone has to decide whether they want to focus on God, or have less focus and attend to the cares of a potential mate/mate.
1 Cor 7
32 I would like you to be free from concern. An unmarried man is concerned about the Lord’s affairs—how he can please the Lord. 33 But a married man is concerned about the affairs of this world—how he can please his wife— 34 and his interests are divided. An unmarried woman or virgin is concerned about the Lord’s affairs: Her aim is to be devoted to the Lord in both body and spirit. But a married woman is concerned about the affairs of this world—how she can please her husband. 35 I am saying this for your own good, not to restrict you, but that you may live in a right way in undivided devotion to the Lord.