Hmm, well my problem is hardly that similar but I don't see my current relationship ever ending, nor would I want it to. It's amazing and I love him. But. I only slept with a few people before, and not that many times, I just feel like it would have been nice to have a gone a bit more crazy and have sampled a bit more of what was out there sex wise before settling down.
The way I see it - either my relationship lasts, which is great. Or it doesn't - and if it doesn't there must be a good reason for this, and it would be for the best, plus it would allow me to shag a few more hot guys!