It seems to be a boundary - he was okay with me being with L, but that was only because she got there first.
And yes, I have thought of that. Right now it doesn't matter, because there is no way I'm looking for a second or even opening that possibility. It's caused me and the people I love too much grief. If I feel more comfortable with it in the future or find the right person (and it would have to REALLY be the right person for me to chance it), we'll have some talking to do.