This may be quite tame but here goes. If one of my wifes friend calls her on the phone and I know they are going to talk for some time I get my wife to sit on my face and I suck her pussy while she is talking.
I takes a while but eventually I can make her cum, she has to be dead quiet so that her friend don't know what we are doing and normally she will hum and ha a lot just before an orgasm.
We have done this with at least 4 or 5 different friends many times (all female) and I don't think any of them have known
