My husband and I ran together once, 16 years ago, for about one block. LOL
He decided to join me for a run, but he took off like gang-busters (showing off I think as it was shortly after we'd met), and I managed to keep up with him for one block at which point I slowed my pace and he ran ahead. I caught up to him huffing and puffing about 2 blocks later when he advised me that running was not for him so he went home and I finished my 3 miler at my slow and steady pace. LOL. That was the end of our running as a couple.
However, I have since then gone on a few short runs with my daughter to try to teach her some mental tricks to be able to finish "The Mile" at school, and with my son who can outrun me anyday of the week but is still willing to keep my pace to have some Mom-Son time (how long will that last? he's 11 now - sniff sniff). The only thing better than running with your spouse is running with your kids! And I'm ever so grateful that my husband enables me to get in those long runs by watching the kids when necessary. I couldn't ask for a more supportive spouse.