This is for you guys in relationships. I hear from a lot guys (and women too), who say they get bored by the safety that relationships bring.
My retort to them is that they are with the wrong person. I don't believe safety and boredom have anything to do with each other in a relationship. Boredom can and often does arise from a lack of safety. Here's what I mean:
When do most people take risks? When they believe everything will be all right - when they'll come out of the risk safely!
If you're bored in your relationship, it's because you don't trust each other enough to take risks together - whether it's bringing in a sex toy or another person, or just being honest with the other person about your likes and dislikes (usually in bed, but other areas too).
Instead, to be "safe", they simply tolerate their lack of satisfaction in the relationship until they feel so confined and bored, they have to do something drastic to break out of it.
If you have your guard up, you're not safe, and you stay on the much beaten path to keep yourself protected, eventually getting bored and moving on.
Try being honest with the other person about your desires and pet peeves, through actions or words. You're only truly safe if you let your guard down. And when you're safe, you can take risks which keeps relationship fresh.