Hey. If I don't have the answers at least I can make you laugh, huh?
So if you are looking for casual friends why do you want to limit the choices to lesbians? I don't often disclose it but since this thread seems right - I find that being bisexual offers more options particularly if it turns into a group thing. (Former Wild Thing here)

I would like to have some casual friends of either sex but I live very rural and don't get off the farm much. There was a singles group that I went to once and had dinner and then listened to a band but I am kind of sour on that idea because in casual conversation with the group I mentioned the general area where I lived on my farm and when the group finished dinner and went to hear the band there was this total dweeb guy that kept hitting on me and I was trying to be polite but not interested and then when I went to leave he offered to walk me to my car. I said, no thanks, I will be fine. Then one of the other women said let him walk out with you it can be dangerous. I didn't really want to tell them that I had a gun in my purse and I have good aim so I just shut up and he went out with me, asked for my number, I declined. I don't know how many hours he must have spent driving around that week but one day he found my car and knocked on my door. I was stunned. It had never occurred to me that he might want to see what I was driving to find me. I guess I must have had the look of satan in my eyes because I walked out and said, You. Need. To. Leave. Here. Right. Now. Don't. Come. Back. He totally got that I was quite serious and he got in his car pronto and left and that was the last I ever saw of him. Still it spooked me and I was hypervigilant waiting for the nut to come back. Dumb f***. So that kind of poisoned me against going back to the singles group. I have thought of going back because I did enjoy chatting with the women even though the men were slim pickens. I guess I just tell the dweebs to f*** off and forget politeness.
So are you still laughing or have you decided that I am a deranged nut? There isn't an exclusion in this community against the deranged, is there? If so, I guess I should just leave quietly.