Wow, a lot to unpack here. The best set of circumstances is if the girls are into each other or at least can pretend to be. Surprised you can't find enough to keep you busy with two girls. If one girl is riding you cowgirl, you have more options of course, but even still there's plenty you can do and only if you want to. For God's sake man, you have fingers, lip, toes, put them to work, or let them do the work. Two girls who know how to work together will keep you plenty busy. As for condom swapping, there's only one remedy for that, and only if you are up for that. People, help this brother out, and give him some tips. I have talked myself into another threesome down in Chinatown. Over and out.