Coming To Terms

My wife and I have been married almost 20 years now. I've known since we were first married that there was an interest in women, but up until now it's been fantasies, stories, and the like. Recently she confided in me that she wanted to take the next step and fill a void emotionally. We discussed for a long time, and I agreed provided that she share stories. Seems a bit selfish when I think on it but anyhow.

She has been seeing another married woman for a little over a month now. I've met her and she seems very nice. She also seems very concerned that both of the husbands are okay with the arrangement. (Neither of us are a part of the relationship, again agreed upon up front).

What a dramatic change I have seen in the past few weeks. She's like a little schoolgirl with the texting and grinning. I'm happy for her - however, here's where my insecurity comes in.

I can't help thinking where does this lead? In a male/female relationship (or I guess any relationship) where both parties are single - there seems to be a build up over time - love. Maybe I'm overthinking this but I can't help wonder - she and her girlfriend are both happily married, both couples have kids, is there a next step? When I try to talk to her about it she says she doesn't know what's next which doesn't make me feel much better.

She's asked me to trust her not to hurt me. So far, I'm trying. I'm obviously not 100% there yet as I'm here looking for others in similar situations. What has worked/not worked for others in this situation? Am I getting myself worked up for nothing, or am I setting myself up for unhappiness down the road?

Thanks,
Matt
CincyMatt CincyMatt
36-40, M
Nov 25, 2012