Only 3 bad experiences?? Consider yourself lucky
Over the years, we have had the same problem with some couples. Typically, the "limp" male problem has to do with drugs/alcohol, or the fact that the couples are new to swinging and the male partner is felling a bit stressed at seeing his partner enjoy herself. This has happened to us too many times to count, and actually turned us right off of "newbies" for a while. We are there for fun and sex, not to deal with the issues another couple may have!
But, I do have to say that I was somewhat shocked that you stopped your husband's enjoyment. We would never do that to one another as we do share in the pleasure we each receive. Carol, being on the receiving end of inattention or inactivity many times, has never even hinted for me to stop what I was doing and enjoying. We have been in similar situations where the male partner couldn't perform, and ended up stopping me and his partner, but we've never experienced the woman stopping the fun.
I should point out that we are not into "Swapping" where the partners exchange and play like that. We are more into the big group experience (even with one other couple) where everyone is together enjoying the play. Primarily, this is because Carol is fully Bisexual, and likes to experience everything together.
My advice is to find more experienced partners who are more comfortable with the Lifestyle, and cut down on the drinking beforehand. If you meet a couple, and see that they are drinking quite a bit, just move on. While some have no problem handling their alcohol, others just can't perform (and always say, "WOW! This never happened before!")
Danny & Carol